共查询到20条相似文献,搜索用时 31 毫秒
1.
Tianhong Zhou Guozhen Zhang Hao Yang Hongwei Zhang Ruini Suo Yingshuang Xie Gang Liu 《RSC advances》2018,8(49):28179
Effective visible-light-driven Ag3PO4/GO/NiFe2O4Z-scheme magnetic composites were successfully fabricated by a simple ion-exchange deposition method. The Ag3PO4/GO/NiFe2O4 (8%) composite exhibited excellent photocatalytic activity (degradation efficiency was ∼96% within 15 min and kinetic constant reached 0.1956 min−1) and stability when compared to Ag3PO4, NiFe2O4, and Ag3PO4/NiFe2O4 for rhodamine B (RhB) degradation. Furthermore, by electrochemical and fluorescence measurements, the Ag3PO4/GO/NiFe2O4 (8%) material also showed larger transient photocurrent, lower impedance, and longer fluorescence lifetime (7.82 ns). Comparing the activity result dependence with characterization results, it was indicated that photocatalytic activity depended on fast charge transfer from Ag3PO4 to NiFe2O4 through GO sheet. The h+ and ·O2− species played important roles in RhB degradation under visible-light. A possible Z-scheme mechanism is proposed over the Ag3PO4/GO/NiFe2O4 (8%) composite. This study might provide a promising visible light responsive photocatalyst for the photocatalytic degradation of organic dyes in wastewater.Effective visible-light-driven Ag3PO4/GO/NiFe2O4Z-scheme magnetic composites were successfully fabricated by a simple ion-exchange deposition method. The composites exhibited excellent photocatalytic activity and stability for RhB degradation. 相似文献
2.
Visible-light-driven Ag3PO4/graphite-like carbon nitride/Ag2WO4 photocatalysts with different weight fractions of Ag3PO4 were synthesized. Ag2WO4 nanorods with a scale of 500 nm to 3 μm were prepared by using a hydrothermal reaction. Via a facile deposition–precipitation technique, graphite-like carbon nitride (g-C3N4) quantum dots and Ag3PO4 nanocrystals were then deposited onto the surface of Ag2WO4 nanorods sequentially. Under visible-light irradiation (λ > 420 nm), the Ag3PO4/g-C3N4/Ag2WO4 nanorods degraded Rh B efficiently and displayed much higher photocatalytic activity than that of pure Ag2WO4 and the g-C3N4/Ag2WO4 composite, and the Ag3PO4/g-C3N4/Ag2WO4 hybrid photocatalyst with 30 wt% of Ag3PO4 exhibited the highest photocatalytic activity. The quenching effects of different scavengers demonstrated that reactive h+ and ·O2− played the major roles in Rh B degradation. It was elucidated that the excellent photocatalytic activity of Ag3PO4/g-C3N4/Ag2WO4 for the degradation of Rh B under visible light (λ > 420 nm) can be ascribed to the efficient separation of photogenerated electrons and holes through the Ag3PO4/g-C3N4/Ag2WO4 heterostructure.The ternary heterostructured Ag3PO4/g-C3N4/Ag2WO4 photocatalysts were successfully synthesized. The ternary composites exhibited enhanced photocatalytic activity. 相似文献
3.
Herein, a novel ternary nanocomposite AgCl/Ag3PO4/g-C3N4 was successfully synthesized via sedimentation precipitation and ion exchange method. The photocatalytic performance of the as-prepared AgCl/Ag3PO4/g-C3N4 nanocomposite was investigated via photocatalytic degradation of methylene blue (MB), methylparaben (MPB) and inactivation of E. coli under visible light irradiation. The AgCl/Ag3PO4/g-C3N4 composite presented the optimal photocatalytic performance, degrading almost 100% MB and 100% MPB, respectively. The excellent stability of AgCl/Ag3PO4/g-C3N4 was also verified in the cycle operations; the degradation efficiency of MPB could still be maintained at 85.3% after five cycles of experiments. Moreover, the AgCl/Ag3PO4/g-C3N4 composite displayed more superior photocatalytic inactivation efficiency with 100% removal of E. coli (7-log) in 20 min under visible light irradiation. The efficient photo-generated charge separation originated from a strong interaction in the intimate contact interface, which was confirmed by the results of photocurrent and EIS measurements. In addition, radical trapping experiments revealed that hole (h+) was the predominant active species in the photocatalytic system. Based on the experimental results, a photocatalytic mechanism for the degradation of parabens over AgCl/Ag3PO4/g-C3N4 was also proposed. We believe that this work provides new insights into the multifunctional composite materials for the applications in solar photocatalytic degradation of harmful organic compounds and common pathogenic bacteria in wastewater.A noval ternary nanocomposite AgCl/Ag3PO4/g-C3N4 was successfully synthesized for photocatalytic degradation of methylene blue, methylparaben and inactivation of E. coli under visible light irradiation, showing excellent photocatalytic degradation performance and stability. 相似文献
4.
A novel visible-light-driven Z-scheme heterojunction, Bi2WO6/Ag2S/ZnS, was synthesized and its photocatalytic activity was evaluated for the treatment of a binary mixture of dyes, and its physicochemical properties were characterized using FT-IR, XRD, DRS and FE-SEM techniques. The Bi2WO6/Ag2S/ZnS Z-scheme heterojunctions not only facilitate the charge separation and transfer, but also maintain the redox ability of their components. The superior photocatalytic activity demonstrated by the Z-scheme Bi2WO6/Ag2S/ZnS attributes its unique properties such as the rapid generation of electron–hole pairs, slow recombination rate, and narrow bandgap. The performance of the Bi2WO6/Ag2S/ZnS was evaluated for the simultaneous degradation of methyl green (MG) and auramine-O (AO) dyes, while the influences of the initial MG concentration (4–12 mg L−1), initial AO concentration (2–6 mg L−1), pH (3–9), irradiation time (60–120 min) and photocatalyst dosage (0.008–0.016 g L−1) were investigated through the response surface methodology. The desirability function approach was applied to optimize the process and results revealed that maximum photocatalytic degradation efficiency was obtained at optimum conditions including 6.08 mg L−1 of initial MG concentration, 4.04 mg L−1 of initial AO concentration, 7.25 of pH, 90.58 min of irradiation time and 0.013 g L−1 of photocatalyst dosage. In addition, a possible photocatalytic mechanism of the Bi2WO6/Ag2S/ZnS heterojunction was proposed based on the photoinduced charge carriers.A Z-scheme Bi2WO6/Ag2S/ZnS heterojunction was successfully synthesized as a novel visible-light-driven photocatalyst for the degradation of multiple dye pollutants. 相似文献
5.
Yiqiu Liu Yi Zhou Qijun Tang Qian Li Si Chen Zhuxing Sun Haiqiang Wang 《RSC advances》2020,10(3):1757
To explore an efficient photocatalyst for NO pollution, a direct Z-scheme photocatalytic system is successfully fabricated by coupling Bi2WO6 with NH2-UiO-66 via a simple hydrothermal synthesis technique. The Z-scheme system promotes the NO photocatalytic oxidation activity with an optimum NO removal rate of 79%, which is 2.7 and 1.2 times that obtained by using only pristine Bi2WO6 and NH2-UiO-66, respectively. Simultaneously, superior selectivity for converting NO to NO3−/NO2− is observed. The enhanced photocatalytic performance of the Bi2WO6/NH2-UiO-66 hybrids is attributed to the following two aspects: (i) large specific area of NH2-UiO-66, which exposes more active sites and is beneficial to the adsorption and activation of NO; (ii) outstanding Z-scheme structure constructed between BiWO6 and NH2-UiO-66, which can improve the efficiency of the separation of electron–hole pairs and preserves the strong oxidation ability of hybrids. ESR analysis shows that ·O2− and ·OH contribute to NO removal. A possible photocatalytic mechanism of NO oxidation on the direct Z-scheme photocatalyst (BWO/2NU) under visible light irradiation is proposed. This work displays the BWO/2NU hybrid''s potential for treating low-concentration air pollutants, and the proposed Z-scheme photocatalyst design and promotion mechanism may inspire more rational synthesis of highly efficient photocatalysts for NO removal.To explore an efficient photocatalyst for NO pollution, a direct Z-scheme photocatalytic system is successfully fabricated by coupling Bi2WO6 with NH2-UiO-66 via a simple hydrothermal synthesis technique. 相似文献
6.
A novel floating visible-light photocatalyst (HGMs–TiO2/Ag3PO4) composite was prepared using amino modified low-density hollow glass microspheres (HGMs) as carriers to disperse and support TiO2 and Ag3PO4 photocatalysts. The surface morphology, crystal structure and optical properties of the HGMs–TiO2/Ag3PO4 composites were characterized and the Ag3PO4 content on the surface of the microspheres was determined by atomic absorption spectrometry (AAS). Methylene blue (MB) was chose as the organic pollutant to investigate the visible-light catalytic properties of the HGMs–TiO2/Ag3PO4 composites. For HGM composite photocatalysts, when the theoretical mass ratio of TiO2 to Ag3PO4 on the surface of HGMs is 1 : 1.5, the visible-light catalytic activity of the composite is superior to pure Ag3PO4 and a TiO2/Ag3PO4 photocatalyst with a mass ratio of 1 : 1.5 under the same conditions, due to the increased light-contact area and the photocatalytic active sites, since the TiO2 and Ag3PO4 particles can be well dispersed on the surface of the floating HGMs. Furthermore, the deposits of TiO2 and Ag3PO4 on the HGM surface form a heterostructure, facilitating the separation of electron–hole (e− – h+) in the energy band, and elevating the photocatalytic activity and cycle stability of Ag3PO4. This work indicates that floating HGMs–TiO2/Ag3PO4 composites could become a promising photocatalyst for organic dye removal due to the low cost and high visible-light responsiveness.The amino modified low-density hollow glass microspheres were used as carriers of TiO2 and Ag3PO4 photocatalysts to prepare the floating visible-light photocatalyst composite. 相似文献
7.
A high-performance photocatalytic nanocomposite consisting of silver phosphate-based particles with GO and RGO was synthesized by co-precipitation and hydrothermal methods. Ag3PO4 was prepared by a co-precipitation method. The as-prepared Ag3PO4 nanocomposites were characterized by different analyses. The results demonstrated that the Ag3PO4 particles were well dispersed on the graphene-based surfaces. The photocatalytic performance of the GO/RGO/Ag3PO4 nanocomposite was evaluated for the photodegradation of methylene blue (MB) under exposure to visible light (xenon lamp λ > 400 nm). The degradation rate was about 98% in 5 min. The enhancement in photocatalytic performance is attributed to the simultaneous presence of RGO and GO, which show significantly high absorption of organic molecules on the surface of GO/RGO, allowing the effective transfer and separation of photogenerated electrons. In addition, this modified structure can be in situ synthesized on dead coral structures that can be used in future real case-studies of the degradation of other organic pollutants. The ingredient of these composites, however, is about 93% Ag3PO4.A high-performance photocatalytic nanocomposite consisting of silver phosphate-based particles with GO and RGO was synthesized by co-precipitation and hydrothermal methods. 相似文献
8.
Jianchao Ma Shurong Yang Huixian Shi Jin Pang Xiaopeng Zhang Yuxing Wang Hongqi Sun 《RSC advances》2020,10(27):16027
Efficient visible-light-driven heterojunction photocatalysts have attracted broad interest owing to their promising adsorption and degradation performances in the removal of organic pollutants. In this study, a mesoporous exfoliated bentonite (EB)/Ag3PO4/AgBr (30%) photocatalyst was obtained by stripping and exfoliating bentonite as the support for loading Ag3PO4 and AgBr. The particle size ranges of Ag3PO4 and AgBr were about 10–30 nm and 5–10 nm, respectively. The exfoliated bentonite could greatly improve the dispersion and adsorption of Ag3PO4 and AgBr, and significantly enhance the stability of the material during paraben photodegradation. 0.2 g L−1 methylparaben (MPB) was completely decomposed over the EB/Ag3PO4/AgBr (30%) in 40 min under visible light irradiation. In addition, the photocatalytic activity of EB/Ag3PO4/AgBr (30%) remained at about 91% after five recycling runs manifesting that EB/Ag3PO4/AgBr (30%) possessed excellent stability. Radical quenching tests revealed that holes (h+) and hydroxyl radicals (·OH) were the major radicals. They attacked the side chain on the benzene ring of parabens, which were gradually oxidized to the intermediates, such as benzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, azelaic acid, and eventually became CO2 and H2O. The enhancement of photocatalytic activity and photo-stability could be ascribed to the stable structural characteristics, enlarged surface area, high absorption ability, and improved light absorption ability from loading Ag3PO4 onto EB. Meanwhile, the matched energy levels of Ag3PO4 and AgBr made the photoelectron–hole pairs separate and transfer effectively at the interfaces. As a result, the photocatalytic properties of EB/Ag3PO4/AgBr (30%) composites were enhanced.A mesoporous exfoliated bentonite (EB)/Ag3PO4/AgBr (30%) photocatalyst was designed to combine various functions to achieve efficient photodegradation of parabens. 相似文献
9.
We report the considerable advantages of direct Z-scheme photocatalysts by immobilizing high-quality CdS quantum dots (QDs) in the channels of graphene-hybridized and supported mesoporous titania (GMT) nanocrystals (CdS@GMT/GR) under facile hydrothermal conditions. The photocatalysts have been characterized by XRD, PL, XPS, SEM, DRS, TEM, EIS, and N2 adsorption. CdS QDs primarily serve as photosensitizers with a unique pore-embedded structure for the effective utilization of the light source. This direct Z-scheme CdS@GMT/GR exhibits higher photocatalytic activity than CdS/GR, GMT/GR, or CdS@MT. In addition, the rate constant of CdS@GMT/GR-2 is approximately twice the sum of those of CdS@MT and GMT/GR, because GR played the role of hole-transporting and collection layer as well as the hybridization level formation in terms of hybridizing MT and serving as a support. Therefore, the GR content tunes the energy band, affects the surface area, and controls the interfacial hole transfer and collection rate of the direct Z-scheme system. Furthermore, CdS@GMT/GR retains its high performance in repeated photocatalytic processes. This can be attributed to the fact that GR prevents QDs from photocorrosion by means of the hole-transporting and collection effect. A possible reaction mechanism is proposed. This work provides a promising strategy for the construction of highly efficient visible-light-driven photocatalysts to reduce the growing menace of environmental pollution.CdS@GMT/GR exhibits high photocatalytic activity due to its direct Z-scheme structure obtained by immobilizing CdS quantum dots in the channels of GMT nanocrystals. 相似文献
10.
Feifei Zhao Kyu Kyu Khaing Dongguang Yin Bingqi Liu Tao Chen Chenglong Wu Kexian Huang LinLin Deng Luqiu Li 《RSC advances》2018,8(74):42308
A novel heterostructured nanocomposite UCNPs@SiO2@Ag/g-C3N4 was developed for the first time to substantially boost the solar-light driven photocatalytic activity of g-C3N4. Its photocatalytic properties and photocatalytic mechanism were investigated. The as-synthesized photocatalyst with excellent improvement in the solar absorption and separation efficiency of photoinduced electron–hole pairs exhibited optimum solar-induced photocatalytic activity in dye degradation and hydrogen production. The experimental results showed that the rates of degradation of Rhodamine B (RhB) and hydrogen evolution were about 10 and 12 times higher than that of pristine g-C3N4, respectively. The excellent photocatalytic activity was attributed to the synergetic effect of upconversion nanoparticles (UCNPs) and Ag nanoparticles (NPs) on the modification of the photocatalytic properties of g-C3N4, resulting in a broad light response range for g-C3N4 as well as the fast separation and slow recombination of photoinduced electron–hole pairs. This study provides new insight into the fabrication of g-C3N4-based nanocomposite photocatalysts with high catalytic efficiency through the artful assembly of UCNPs, Ag NPs and g-C3N4 into a hetero-composite nanostructure. The prominent improvement in photocatalytic activity enables the potential application of g-C3N4 in the photocatalytic degradation of organic pollutants and hydrogen production utilizing solar energy.A novel heterostructured nanocomposite UCNPs@SiO2@Ag/g-C3N4 was developed for the first time to substantially boost the solar-light driven photocatalytic activity of g-C3N4. 相似文献
11.
Shengqi Zhang Tao Yu Hui Wen Rui Guo Juanjuan Xu Ruixia Zhong Xian Li Junhua You 《RSC advances》2020,10(29):16892
WO3/Ag3PO4 with different weight ratios were prepared by ultrasonic assisted two-step deposition method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The photocatalytic activities of all samples were evaluated by the degradation of rhodamine B (RhB) under visible light irradiation. WA-60 shows the highest photocatalytic activity in the WA-x series composite, while the photocatalytic activity of WAA-60 is the best among all samples. The free radical trapping experiments show that photogenerated holes (h+) are the main active species. The Ag nanoparticles produced by the decomposition of Ag3PO4 are located at the interface of Ag3PO4/WO3, which promotes the separation efficiency of photogenerated electrons and holes. To further explain the photocatalytic mechanism, electrochemical and physical tests are introduced to explore the flow of electrons inside the catalyst.WO3/Ag3PO4 with different weight ratios were prepared by ultrasonic assisted two-step deposition method. 相似文献
12.
Yi-en Du Wanxi Li Yang Bai Zewen Huangfu Weijin Wang Ruidong Chai Changdong Chen Xiaojing Yang Qi Feng 《RSC advances》2020,10(41):24555
In this study, TiO2/Ag3PO4 composites based on anatase TiO2 nanocrystals with co-exposed {101}, {010}/{100}, {001} and [111]-facets and Ag3PO4 microcrystals with irregular and cubic-like polyhedron morphologies were successfully synthesized by combining hydrothermal and ion-exchange methods. The anatase TiO2 nanocrystals with different high-energy facets were controllably prepared via hydrothermal treatment of the exfoliated [Ti4O9]2−/[Ti2O5]2− nanosheet solutions at desired pH values. The Ag3PO4 microcrystal with different morphologies was prepared via the ion-exchange method in the presence of AgNO3 and NH4H2PO4 at room temperature, which was used as a substrate to load the as-prepared anatase TiO2 nanocrystals on its surface and to form TiO2/Ag3PO4 heterostructures. The apparent rate constant of the pH 3.5-TiO2/Ag3PO4 composite was the highest at 12.0 × 10−3 min−1, which was approximately 1.1, 1.2, 1.4, 1.6, 13.3, and 24.0 fold higher than that of pH 0.5-TiO2/Ag3PO4 (10.5 × 10−3 min−1), pH 7.5-TiO2/Ag3PO4 (10.2 × 10−3 min−1), pH 11.5-TiO2 (8.8 × 10−3 min−1), Ag3PO4 (7.7 × 10−3 min−1), blank sample (0.9 × 10−3 min−1), and the commercial TiO2 (0.5 × 10−3 min−1), respectively. The pH 3.5-TiO2/Ag3PO4 composite exhibited the highest visible-light photocatalytic activity which can be attributed to the synergistic effects of its heterostructure, relatively small crystal size, large specific surface area, good crystallinity, and co-exposed high-energy {001} and [111]-facets. The as-prepared TiO2/Ag3PO4 composites still exhibited good photocatalytic activity after three successive experimental runs, indicating that they had remarkable stability. This study provides a new way for the preparation of TiO2/Ag3PO4 composite semiconductor photocatalysts with high energy crystal surfaces and high photocatalytic activity.TiO2/Ag3PO4 composites with co-exposed {101}, {010}/{100}, {001} and [111]-facets were successfully synthesized by combining hydrothermal and ion-exchange methods. 相似文献
13.
A rapid recombination of photo-generated electrons and holes, as well as a narrow visible light adsorption range are two intrinsic defects in graphitic carbon nitride (g-C3N4)-based photocatalysts. Inspired by natural photosynthesis, an artificially synthesized Z-scheme photocatalyst can efficaciously restrain the recombination of photogenerated electron–hole pairs and enhance the photoabsorption ability. Hence, to figure out the above problems, BiOBr/g-C3N4 composite photocatalysts with different mass ratios of BiOBr were successfully synthesized via a facile template-assisted hydrothermal method which enabled the BiOBr microspheres to in situ grow on the surface of g-C3N4 flakes. Furthermore, to explore the origin of the enhanced photocatalytic activity of BiOBr/g-C3N4 composites, the microstructure, photoabsorption ability and electrochemical property of BiOBr/g-C3N4 composites were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS) and photocurrent (PC) response measurements. As a result, the introduction of BiOBr on g-C3N4 to constitute a direct Z-scheme heterojunction system can effectively broaden the light absorption range and promote the separation of photo-generated electron–hole pairs. Hence, compared with pure g-C3N4 and BiOBr, the resultant BiOBr/g-C3N4 composites exhibit the remarkable activity of photodegradated rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) under visible light irradiation. Simultaneously, the optimal BiOBr content of the BiOBr/g-C3N4 composites was obtained. The BiOBr/g-C3N4 composites exhibit an excellent photostability and reusability after four recycling runs for degradation RhB. Moreover, the active-group-trapping experiment confirmed that ·OH, ·O2− and h+ were the primary active groups in the degradation process. Based on the above research results, a rational direct Z-scheme heterojunction system is contrastively analyzed and proposed to account for the photocatalytic degradation process of BiOBr/g-C3N4 composites.The morphology, electrochemical property, photoabsorption ability and photocatalytic activity of BiOBr/g-C3N4 composites are discussed. A rational photocatalytic mechanism is proposed. 相似文献
14.
A novel Ag3PO4/SnO2/porcine bone composite photocatalyst was successfully prepared via an ion exchange method, which can convert lignin derivatives into small molecular acids upon exposure to visible light at room temperature at ambient pressure. The composition characterization, optical absorption properties and photocatalytic activities of the Ag3PO4/SnO2/porcine bone composites were thoroughly investigated. The certain role of each component of the composites in the degradation reaction was discussed: Ag3PO4 acted as the major active component, while SnO2 and porcine bone as cocatalyst contributed to improve the photocatalytic activity and stability of Ag3PO4. The enhanced activity of the Ag3PO4/SnO2/porcine bone composite may be attributed to the synergistic effect including the matched energy band structures of Ag3PO4 and SnO2 for the decrease in the probability of electron–hole recombination and improved performance in the presence of hierarchical porous porcine bone (hydroxyapatite). This paper also analyzed the change of the molecular weight and structure of sodium lignin sulfonate in the photocatalytic reaction and discussed the possible photocatalytic mechanism of the photocatalyst composite, indicating that the benzene rings of guaiacol were oxidized into different alkyl acids (maleic acid, oxalic acid, formic acid and methoxy acetic acid).A novel Ag3PO4/SnO2/porcine bone photocatalyst was synthesized for mild depolymerization of lignosulfonate, providing a green approach to utilize lignin derivatives. 相似文献
15.
Fengyan Ma Qilin Yang Zhengjun Wang Yahong Liu Jianjiao Xin Jingjing Zhang Yuting Hao Li Li 《RSC advances》2018,8(28):15853
Novel Ag3PO4/Bi2WO6 heterostructured materials with enhanced visible-light catalytic performance were successfully synthesized by assembly combined with a hydrothermal treatment. The microstructures, morphologies, and optical properties of the prepared samples were characterized by multiple techniques. The irregular Ag3PO4 nanospheres dispersed on the surface of Bi2WO6 nanoflakes, and their catalytic performances were evaluated via the degradation of organic pollutants including rhodamine B (RB), methylene blue (MB), crystal violet (CV), methyl orange (MO), and phenol (Phen) under visible-light irradiation. The resulting Ag3PO4/Bi2WO6 heterostructured materials displayed higher photocatalytic activity than that of either pure Bi2WO6 or Ag3PO4. The enhanced photocatalytic activity was due to the good formation of heterostructures, which could not only broaden the spectral response range to visible light but also effectively promoted the charge separation. Meanwhile, the reasonable photoreactive plasmonic Z-scheme mechanism was carefully investigated on the basic of the reactive species scavenging tests, photoelectrochemical experiments, and photoluminescence (PL) spectrum. In addition, the excellent photostability of Ag3PO4/Bi2WO6 was obtained, which Ag formed at the early photocatalytic reaction acted as the charge transmission-bridge to restrain the further photoreduction of Ag3PO4.Novel Ag3PO4/Bi2WO6 heterostructured materials were synthesized by assembling Ag3PO4 irregular nanospheres on the surface of Bi2WO6 nanoflakes and showed superior visible-light photocatalytic activity owing to the good formation of heterostructures. 相似文献
16.
Low visible light response and rapid recombination of photogeneration charge carriers have always been the main factors limiting the advanced application of g-C3N4 (CN). Element doping has been confirmed to be an efficient method to improve the photocatalytic performance of CN. Here, a series of Cu and O co-doped porous g-C3N4 (Cu/O-PCN) nanomaterials were successfully fabricated by a facile one-pot thermal polymerization approach for the first time. Compared to pure CN, the resulting Cu/O-PCN exhibited remarkably enhanced visible-light-driven photocatalytic activity towards levofloxacin (LEVO) degradation. The optimized sample of 0.5% Cu doped (Cu/O-PCN-3) presented the highest degradation rate constant of 0.0676 min−1, which was about 6.2 times higher than that of CN. Furthermore, a substantial decrease in the residual toxicity against E. coli was observed after photocatalytic degradation treatment. The superior photocatalytic performance of Cu/O-PCN was mainly attributed to the synergistic advantages of stronger visible light response, larger specific surface area, and the more effective separation and transfer of photogenerated charge carriers. Moreover, according to the trapping experiments, ·O2− and h+ were the major oxygen active species in the photocatalytic degradation process. Finally, the possible enhanced photocatalytic mechanism over Cu/O-PCN was proposed.Cu and O co-doped porous g-C3N4 with outstanding photocatalytic degradation of levofloxacin performance was synthesized by a one-pot thermal polymerization approach. 相似文献
17.
Hengfei Qin Yuanhui Zuo Jutao Jin Wenlong Wang Youlong Xu Lifeng Cui Haifeng Dang 《RSC advances》2019,9(42):24483
The designed synthesis of noble-metal-free photocatalysts with hierarchical heteroassemblies in a facile, mild and eco-friendly way becomes more and more important, because we can explore the novel properties and applications of novel heterostructures via this method. Herein we report a two-step aqueous strategy for novel hierarchical heterostructures of ZnO nanorod (NR) arrays grown on graphitic carbon nitride (g-C3N4). The novel g-C3N4/ZnO NR heterostructures that integrate g-C3N4 and ZnO NR via high-quality g-C3N4–ZnO heterojunctions have beneficial properties such as high specific surface area (SSA), open spatial architecture, good electronic conductivity, and effective charge transfer interfaces, and are promising in many related areas such as water splitting, solar cells, etc. As a noble-metal-free and visible-light-responsive photocatalytic material, a typical g-C3N4/ZnO NR photocatalytic system exhibits enhanced photocatalytic activity toward H2 evolution, almost 3.5 times higher than that of pure g-C3N4. The superior photocatalytic property can be ascribed to the synergistic effect of the unique g-C3N4/ZnO NR heterostructures.The designed synthesis of photocatalysts with hierarchical heteroassemblies in a facile, mild and eco-friendly way becomes more and more important, since we can explore the novel properties and applications of novel heterostructures via this method. 相似文献
18.
Mudassar Sher Mohsin Javed Sammia Shahid Shahid Iqbal Muhammad Azam Qamar Ali Bahadur Muhammad Abdul Qayyum 《RSC advances》2021,11(4):2025
The in situ growth of well-dispersed Cd-doped ZnO nanoparticles (Cd-ZnO NPs) on graphitic carbon nitride (g-C3N4) nanosheets was successfully achieved through the co-precipitation method for the formation of Cd-doped ZnO nanocomposites with g-C3N4 (Cd-ZnO/g-C3N4 NCs). The effect of different compositions of ternary nanocomposites (Cd-ZnO/g-C3N4 NCs) on photocatalytic properties was investigated. Ternary NCs, in which 60% g-C3N4 hybridized with 7% Cd-doped ZnO (g-C3N4/Cd-ZnO) NCs were proven to be optimum visible-light-driven (VLD) photocatalysts for the degradation of methylene blue (MB) dye. The enhanced photodegradation of MB is mainly due to the increase in the generation of photogenerated charge carriers (reactive oxygen species (ROS), O2−, and ˙OH radicals). The electron spin resonance (ESR) experiment revealed that the superoxide and hydroxyl radicals were the leading species responsible for the degradation of MB. Moreover, the NC exhibited tremendous stability with a consistently high MB degradation rate for 10 successive catalytic cycles. The structural and optical properties of CdO, ZnO NPs, Cd-ZnO NPs, g-C3N4 NSs, and g-C3N4/Cd-ZnO NCs were investigated via XRD, SEM, EDX, TEM, FTIR spectroscopy, UV-Vis spectroscopy, ESR spectroscopy, and PL spectroscopy techniques. The synthesized photocatalysts were also applied against Gram-positive and Gram-negative bacterial strains to evaluate their antibacterial activities.The controlled design of novel Z-scheme g-C3N4/Cd-ZnO heterojunction via chemical co-precipitation technique. 60% g-C3N4 hybridized with 7% Cd-doped ZnO (g-C3N4/Cd-ZnO) NCs have been proved to be optimum visible-light-driven (VLD) photocatalysts. 相似文献
19.
In this work, fullerene-modified magnetic silver phosphate (Ag3PO4/Fe3O4/C60) nanocomposites with efficient visible light photocatalytic and catalytic activity were fabricated by a simple hydrothermal approach. The composition and structure of the obtained new magnetically recyclable ternary nanocomposites were completely characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Brunauer–Emmett–Teller (BET) specific surface area analysis, vibrating sample magnetometery (VSM), diffuse reflectance spectroscopy (DRS), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy and transmission electron microscopy (TEM). This novel magnetically recyclable heterogeneous fullerene-modified catalyst was tested for the H2O2-assisted photocatalytic degradation of MB dye under visible light. The results show that about 95% of the MB (25 mg L−1, 50 ml) was degraded by the Ag3PO4/Fe3O4/C60 nanocomposite within 5 h under visible light irradiation. The catalytic performance of the Ag3PO4/Fe3O4/C60 nanocomposite was then examined for 4-nitrophenol (4-NP) reduction using NaBH4. This new nanocomposite showed that 4-NP was reduced to 4-aminophenol (4-AP) in 98% yield with an aqueous solution of NaBH4. In both photocatalytic and catalytic reactions, the Ag3PO4/Fe3O4/C60 nanocomposite exhibited higher catalytic activity than pure Ag3PO4. Moreover, the Ag3PO4/Fe3O4/C60 nanocomposite could be magnetically separated from the reaction mixture and reused without any change in structure. The antibacterial activity of the nanocomposites was also investigated and they showed good antibacterial activity against a few human pathogenic bacteria.Fullerene-modified magnetic silver phosphate (Ag3PO4/Fe3O4/C60) nanocomposites prepared by a hydrothermal route were used as photocatalysts/catalysts for the efficient degradation and reduction of MB dye and 4-nitrophenol, respectively. 相似文献
20.
Yu Qiao Qian Han Dong Li Hongji Li Bing Wei Guangbo Che Wei Jiang Weisheng Guan 《RSC advances》2019,9(71):41591
A novel Ag/metal–organic framework/graphitic carbon nitride (Ag/HKUST-1/g-C3N4, AHC) photocatalyst was prepared via an in situ growth strategy and photo-deposition technique for environmental remediation. The as-obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherm measurement, UV-vis diffuse reflection spectroscopy (UV-vis DRS), and photoluminescence (PL) spectroscopy. The results indicated that the hybrids have large surface area, mesoporous structure and enhanced visible-light absorption. The as-prepared hybrid samples exhibited considerable improvement in photocatalytic activity and stability for rhodamine B (RhB) degradation under visible light irradiation (λ > 420 nm). In addition, they also have good adsorption properties. Compared to the pure g-C3N4 and Ag/g-C3N4, the 5% AHC photocatalyst showed superior photocatalytic activity. Moreover, 5% AHC exhibits good photocatalytic activity even after four cycles. Additionally, the active species trapping and electron spin resonance (ESR) experiments indicated that h+ and ·OH were the main active species.A novel AHC photocatalyst was prepared via in situ growth strategy and photo-deposition technique. The as-prepared hybrid samples have good photocatalytic activity and stability for Rh B degradation under visible-light irradiation. 相似文献