Retraction: Synthesis and characterization of Mn/Co/Ti LDH and its utilization as a photocatalyst in visible light assisted degradation of aqueous Rhodamine B

Retraction of ‘Synthesis and characterization of Mn/Co/Ti LDH and its utilization as a photocatalyst in visible light assisted degradation of aqueous Rhodamine B’ by Priyadarshi Roy Chowdhury and Krishna G. Bhattacharyya, RSC Adv., 2016, 6, 112016–112034.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article following a misconduct investigation carried out by Gauhati University.There are repeating motifs within the AFM image in Fig. 7A. Gauhati University have informed us that they have concluded that the AFM image is devoid of authenticity and has been manipulated or altered by the authors.Signed: Andrew Shore, Executive Editor, RSC AdvancesDate: 4^th February 2019     

Diatomite/Cu/Al layered double hydroxide hybrid composites for polyethylene degradation

A diatomite/Cu/Al layered double hydroxide hybrid composite (DI-LDH) was synthesized using the hydrothermal method. The synthesized DI-LDH composites were characterized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and the Brunauer–Emmett–Teller (BET) method. Polyethylene degradation over DI-LDH was studied in a batch reactor. DI-LDH showed layered structures, indicating that the diatomite/Cu/Al double hydroxide hybrid was successfully synthesized. A significant decrease in the degradation temperature and the released amounts of CO and CO₂ was observed in the DI-LDH catalytic degradation reaction, which indicated that DI-LDH was helpful for the polyethylene degradation reaction. The X-ray photoelectron spectroscopy (XPS) results suggested that the reaction of Cu²⁺ → Cu⁺ occurred in polyethylene catalytic pyrolysis, which resulted in the decrease in the released CO amount. DI-LDH may be a potential environmental catalyst that can be applied to treat LDPE waste.

DI-LDH that can reduce the pyrolysis temperature of LDPE and the release of carbon monoxide (CO) and carbon dioxide (CO₂).     

Preparation and application of layered double hydroxide nanosheets

Layered double hydroxides (LDH) with unique structure and excellent properties have been widely studied in recent years. LDH have found widespread applications in catalysts, polymer/LDH nanocomposites, anion exchange materials, supercapacitors, and fire retardants. The exfoliated LDH ultrathin nanosheets with a thickness of a few atomic layers enable a series of new opportunities in both fundamental research and applications. In this review, we mainly summarize the LDH exfoliation methods developed in recent years, the recent developments for the direct synthesis of LDH single-layer nanosheets, and the applications of LDH nanosheets in catalyzing oxygen evolution reactions, crosslinkers, supercapacitors and delivery carriers.

Layered double hydroxides (LDHs) with unique structure and excellent properties have been widely studied in recent years.     

Synthesis of a novel magnetic Caragana korshinskii biochar/Mg–Al layered double hydroxide composite and its strong adsorption of phosphate in aqueous solutions

Phosphate pollution of aquatic ecosystems is of great concern and requires the development of high-performance materials for effective pollution treatment. To realize efficient phosphate removal from aqueous solution, an easily separable magnetic (Fe₃O₄) Caragana korshinskii biochar/Mg–Al layered double hydroxide composite (denoted as FCB/MAC) was synthesized via two-step electro-assisted modification for the first time. Subsequently, the physical and chemical properties of FCB/MAC were characterized. Furthermore, the sorption mechanism for phosphate removal was investigated in detail. The results indicated that Fe₃O₄ and the Mg–Al layered double hydroxide were successfully embedded in the biochar matrix. Moreover, FCB/MAC exhibited a high phosphate adsorption capacity and excellent magnetic properties for easy recovery. The maximum phosphate sorption capacity of FCB/MAC was 252.88 mg g⁻¹, which is much higher than the capacities of most magnetic phosphate adsorbents. In addition, the adsorption kinetics and isotherms indicated that phosphate adsorption by FCB/MAC was controlled by the pseudo-second-order kinetic model and the Langmuir–Freundlich isotherm model. The phosphate adsorption mechanism involves anion exchange, electrostatic attraction, and ligand exchange. After five adsorption–desorption cycles, the phosphate adsorption capacity of FCB/MAC was 25.71 mg g⁻¹ with 51.43% removal efficiency and high recyclability. Thus, the composite prepared in this study is a promising adsorbent for phosphate removal from aqueous solution, and this work provides an excellent reference for constructing novel biochar-based phosphate adsorbents.

This study describes an optimized two-step electro-assisted modification process for the preparation of biochar modified with Fe₃O₄ and Mg–Al layered double hydroxide.     

Tuning the structural properties of cadmium–aluminum layered double hydroxide for enhanced photocatalytic dye degradation

The distinctive layered structure, chemical stability and tunability of layered double hydroxides (LDHs) have led to extensive investigations in various areas of photocatalysis, including photocatalytic water splitting, carbon dioxide photoreduction, and degradation of organic pollutants. Here, a series of visible light active cadmium–aluminum layered double hydroxides (CdAl LDHs) with various Cd²⁺ : Al³⁺ ratios is synthesized via the reaction-diffusion framework (RDF) leading thereby to a hierarchal spherical structure of the LDH. The aim of this study is to develop an optimal CdAl LDH photocatalyst that is activated by solar light irradiation and tested for methylene blue (MB) degradation. The structural and physicochemical properties of the synthesized materials are determined by several imaging and spectroscopic techniques. The photocatalytic study reveals a strong dependence of the photocatalytic activity of the CdAl LDH on the cationic ratio with an optimal performance at a ratio Cd²⁺ : Al³⁺ equal to 3 : 1. A mechanism is proposed whereby the activity is ascribed to the formation of intermediate reactive oxidative species (ROS) during the photodegradation reactions and scrutinised by invoking different ROS quenchers and corroborated by density functional theory (DFT) calculations.

Hierarchical structures of Cd Al LDH of various cationic ratios of Cd : Al are successfully synthesized via the reaction diffusion framework. The obtained microspheres are investigated for the photocatalytic degradation of methylene blue.     

Preparation and characterization of PEG/surface-modified layered double hydroxides as a new shape-stabilized phase change material

A new shape-stabilized phase change material based on polyethylene glycol (PEG) and surface-modified layered double hydroxides (LDHs) was prepared by a solution impregnation method. PEG enabled thermal energy storage and release as a phase change material; 3-aminopropyl triethoxysilane (KH550) was used to modify the surface of LDHs (KH-LDHs) which then acted as a carrier to keep the solid form of the molten PEG at high temperature. The maximum weight percentage of PEG confined in the PEG/KH-LDHs composite was 55%. The detailed structures, thermal properties and UV absorption of the composite were characterized systematically by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermal gravimetric (TG) analysis and UV-vis absorption spectra. Results show that the PEG/KH-LDH composite has a suitable phase change temperature, considerable enthalpy, and good thermal stability as well as remarkable ultraviolet absorption ability. As a new shape-stabilized phase change material, the PEG/KH-LDH composite is expected to contribute to the effort of searching effective measures for thermal management of building and pavement materials.

A new shape-stabilized phase change material based on polyethylene glycol (PEG) and surface-modified layered double hydroxides (LDHs) was prepared. Its potential benefits for thermal management of building and pavement materials is highly expected.     

Design and fabrication of hydrotalcite-like ternary NiMgAl layered double hydroxide nanosheets as battery-type electrodes for high-performance supercapacitors

Hydrotalcite is an abundant mineral in nature and can be cost-effectively prepared in the laboratory, but there is almost no discussion about its application in the field of supercapacitors. Herein, hydrotalcite-like ternary NiMgAl LDHs with unique ultrathin nanosheets were designed and fabricated by a facile hydrothermal method. The preparation conditions, such as Ni/Mg molar ratio and hydrothermal reaction time, are evaluated carefully. The physical and chemical properties were also evaluated by various characterization techniques such as XRD, FIB/SEM, EDS, TEM, XPS and BET. The electrochemical behaviors of present samples were determined by CV, CC and cycling tests in a three-electrode system. As a battery-type electrode material in a supercapacitor, owing to the advantage of its unique layered structure, high specific area and obvious redox states, the fabricated Ni₂MgAl LDH-24 h nanosheets present an outstanding specific capacitance of 219.2 mA h g⁻¹ at a current density of 1 A g⁻¹ and superior cycling stability with 86.1% capacitance retention over 5000 cycles. Although 45.7% capacitance retention is not satisfactory when the current density increases from 1 to 3 A g⁻¹ due to the NiMgAl LDH''s low effective mass and conductivity, it is still a successful case for hydrotalcite application in supercapacitors by doping with Ni²⁺ to achieve high electrochemical performance. The design and fabrication strategy can facilitate the application of the natural hydrotalcite mineral in the energy storage field.

Hydrotalcite is an abundant mineral in nature and can be cost-effectively prepared in the laboratory, but there is almost no discussion about its application in the field of supercapacitors.     

Synthesis and characterization of PEDMCD as a flame retardant and its application in epoxy resins

In this study, a highly effective flame retardant agent, called polybicyclopentaerythritol phosphate-O-4-imino-p-phenylmethane-4-imino-2-chloro-1,3,5-s-triazine (PEDMCD), has been prepared through a direct polycondensation reaction. PEDMCD was incorporated into epoxy resin (EP) to improve the flame retardancy of EP. The molecular structure and thermal stability of PEDMCD were analyzed by nuclear magnetic resonance spectroscopy. Further, the structural properties, composition, and thermal stability of the PEDMCD/EP composite were characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). PEDMCD exhibited both high thermal stability and high flame-retardant performance; these properties were attributed to the phosphorus-containing structure on the side groups and a triazine structure as the molecular backbone, which played the role of a foaming carbon source. With the addition of PEDMCD, the flame-retardant behavior of PEDMCD/EP composites was gradually enhanced. Furthermore, the amount of char residue of the PEDMCD/EP composite at 500 °C was increased from 21% to 34%. The peak value of the mass loss rate of PEDMCD/EP decreased from 0.52 to 0.35 g s⁻¹. Further, the TSP of the sample decreased from 44.2 m² to 24.6 m², and the total oxygen consumption decreased from 64.2 g to 30.4 g. Accordingly, owing to the incorporation of PEDMCD, EP begins to decompose sooner, and the carbon layer formed by decomposition reduces the decomposition rate of the EP matrix. Based on the results of characterization measurements and flame retardancy testing, it is confirmed that PEDMCD exhibits good flame retardancy when applied in EP.

In this study, a highly effective flame retardant agent, called polybicyclopentaerythritol phosphate-O-4-imino-p-phenylmethane-4-imino-2-chloro-1,3,5-s-triazine (PEDMCD), has been prepared through a direct polycondensation reaction.     

Synthesis and characterization of PEDSCD and its application as a flame retardant in epoxy resins

In this study, a flame retardant agent, called PEDSCD, is synthesized through a polycondensation reaction. PEDSCD is a chemically expanded phosphorus-containing flame retardant, which is introduced in epoxy resin (EP) to improve its flame retardancy. The molecular structure and thermal stability of PEDSCD are characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and thermogravimetric analysis, and EP/PEDSCD composites are investigated in detail. EP/PEDSCD exhibits good stability and flame retardancy. These properties are attributed to the triazine structure introduced into the flame retardant system. The triazine structure starts to decompose at a lower temperature and also reacts with the phosphorus element to form P N–, which increases the viscosity of the melt. This inhibits the generation of smoke and reduces the peak of heat release. PEDSCD shows good thermal stability and low flammability. Further, the weight loss from 500 to 800 °C is only 16 wt%, and the residual mass at 800 °C is 32 wt%. With the addition of PEDSCD, the flame retardant quality of the EP/PEDSCD composites is gradually enhanced, and the carbon residue becomes denser, which isolates the heat transfer and inhibits the volatilization of flue gas. The limited oxygen index (LOI) value of 27% and a vertical burning V-0 rating are achieved when PEDSCD is used in combination with ammonium polyphosphate (APP). The cone calorimeter test shows that the peak heat release rate is reduced by 29% and low gas content is generated, which verifies that the combination of PEDSCD and other phosphorus-containing flame retardants exhibits significantly enhanced flame-retardant properties. PEDSCD exhibits a charring and barrier effect in the condensation phase. Overall, using basic characterization and flame retardancy testing, it is proved that PEDSCD exhibits good flame retardancy when added to EP.

In this study, a flame retardant agent, called PEDSCD, is synthesized through a polycondensation reaction.     

Correction: Sustainable waste management and recycling of Zn–Al layered double hydroxide after adsorption of levofloxacin as a safe anti-inflammatory nanomaterial

Correction for ‘Sustainable waste management and recycling of Zn–Al layered double hydroxide after adsorption of levofloxacin as a safe anti-inflammatory nanomaterial’ by Samar M. Mahgoub et al., RSC Adv., 2020, 10, 27633–27651. DOI: 10.1039/D0RA04898D.

The authors regret that, in the originally published version of this article, the name of the author Fatma I. Abo El-Ela was incorrectly displayed as Fatma L. Abo El-Ela. The correct author list is displayed above.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Preparation and photocatalytic application of a S,Nd double doped nano-TiO2 photocatalyst

Correction for ‘Preparation and photocatalytic application of a S, Nd double doped nano-TiO₂ photocatalyst’ by Shuo Wang et al., RSC Adv., 2018, 8, 36745–36753.

In the published article, Liming Bai was incorrectly not listed as the corresponding author. The correct version is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Sustainable waste management and recycling of Zn–Al layered double hydroxide after adsorption of levofloxacin as a safe anti-inflammatory nanomaterial

Inorganic nano-layered double hydroxide (LDH) materials are used in the catalytic field, and have demonstrated great applicability in the pharmacological fields. In the current study, we report Zn–Al LDH as an adsorbent for levofloxacin (levo). The physical and chemical properties of the prepared material before and after adsorption were monitored using X-ray diffraction, Fourier-transform infrared (FT-IR) spectroscopic analysis, energy dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) surface area measurements, high-resolution transmission electron microscopy (HRTEM), and field emission scanning electron microscopy (FESEM). Density functional theory (DFT) calculations for levo and its protonated species were studied at the B3LYP/6-311G (d,p) level of theory. The removal percentage of levo was 73.5%. The adsorption isotherm was investigated using nine different models at pH 9, where the obtained correlation coefficients (R²) using the Redlich–Peterson and Toth models were 0.977. The thermodynamic parameters ΔS°, ΔG° and ΔH° were estimated and discussed in detail. Also, to support the adsorption research field, the applicability of the formed waste after the adsorption of levo onto Zn–Al LDH was investigated for medical purposes. The toxicity of levo in both normal and nanocomposite form was studied. Neither toxicological symptoms nor harmless effects were exhibited throughout the in vivo study. The oral anti-inflammatory activity, tested using 6% formalin to produce edema in the footpad, was manifested as a significant increase of 37% in the anti-inflammatory effect of the Zn–Al LDH/levo nanocomposite compared to levo in its normal form.

Zn-Al LDH was synthesized using the co-precipitation method, characterized and used as an efficient adsorbent for the removal of levofloxacin. The safety and toxicity of the administered Zn-AL LDH/levo as a safe anti-inflammatory material.     

Green synthesis of a AgCl@AgI nanocomposite using Laminaria japonica extract and its application as a visible-light-driven photocatalyst

A AgCl@AgI composite photocatalyst was greenly synthesized using Laminaria japonica extract as the source of halogen anions, and characterized by XRD, SEM, TEM and XPS techniques. The photocatalytic activity and photochemical stability of the AgCl@AgI were investigated by the photodegradation of methyl orange (MO) azo dye under visible light illumination (λ > 420 nm). The AgCl@AgI composite showed good photochemical stability and much higher photocatalytic activity than that of single AgCl and AgI. Mechanism studies showed that the main active species are photoinduced holes (h⁺) and superoxide anion radicals (·O₂⁻). Finally, a plausible mechanism for the separation of photoinduced charge carriers was proposed.

A IgA@lCgA nanocomposite was greenly synthesized with Laminaria japonica extract and applied as a visible-light-driven photocatalyst for organic pollutant degradation.     

Preparation and photocatalytic application of a S,Nd double doped nano-TiO2 photocatalyst

Nowadays, water pollution is getting more and more severe in society, and recently the rational use of photocatalytic technology to treat sewage has become a hot spot for research. Because of the low-cost and environmental friendliness of nano-TiO₂, it has attracted widespread attention. In this paper, we dope sulfur and neodymium into nano-titanium dioxide via a sol–gel method. The synthesized S, Nd-codoped-TiO₂ was characterized via transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, EDS and N₂ adsorption–desorption isotherms. Then the real-life dye reactive red (X-3B) was used as the target degradant to compare the levels of practicality of single-doped and double-doped photocatalysts. The results showed that the photocatalytic activity of S, Nd-codoped-TiO₂ was significantly higher than that of Nd–TiO₂. The double-doped photocatalyst was transformed from anatase to rutile, and the bandgap was reduced considerably. The responding ability to visible light also increased, so S, Nd-codoped-TiO₂ has obvious advantages and has better degradation efficiency for the target degradation products. Under xenon lamp irradiation and pH = 4 conditions, the degradation of reactive red using the new catalyst reached 93.2%. The new catalyst has high practicality and also indicates a new direction for wastewater treatment.

Nowadays, water pollution is getting more and more severe in society, and recently the rational use of photocatalytic technology to treat sewage has become a hot spot for research.     

Expanded graphite/NiAl layered double hydroxide nanowires for ultra-sensitive,ultra-low detection limits and selective NOx gas detection at room temperature

To develop an ultra-sensitive and selective NO_x gas sensor with an ultra-low detection limit, expanded graphite/NiAl layered double hydroxide (EG/NA) nanowires were synthesized by using hydrothermal method with EG as a template and adjusting the amount of urea in the reaction. X-ray diffraction and transmission electron microscopy showed EG/NA3 nanowires with a diameter of 5–10 nm and a length greater than 100 nm uniformly dispersed on the expanded graphite nanosheet (>8 layers). The synergy between NiAl layered double hydroxide (NiAl-LDH) and expanded graphite (EG) improved the gas sensing properties of the composites. As expected, gas sensing tests showed that EG/NA composites have superior performance over pristine NiAl-LDH. In particular, the EG/NA3 nanowire material exhibited an ultra-high response (R_a/R_g = 17.65) with ultra-fast response time (about 2 s) to 100 ppm NO_x, an ultra-low detection limit (10 ppb) and good selectivity at room temperature (RT, 24 ± 2 °C), which could meet a variety of application needs. Furthermore, the enhancement of the sensing response was attributed to the nanowire structure formed by NiAl-LDH in the EG interlayer and the conductive nanonetwork of interwoven nanowires.

Expanded graphite/NiAl-LDH nanowires for ultra-sensitive, ultra-low detection limits and selective NO_x gas detection at room temperature.     

Hierarchically porous SiO2/C hollow microspheres: a highly efficient adsorbent for Congo Red removal

Hierarchically porous SiO₂/C hollow microspheres (HPSCHMs) were synthesized by a hydrothermal and NaOH-etching combined route. The adsorption performance of the prepared HPSCHMs was investigated to remove Congo Red (CR) in aqueous solution. The results show that the synthesized composite possesses a hollow microspherical structure with hierarchical pores and a diameter of about 100–200 nm, and its surface area is up to 1154 m² g⁻¹. This material exhibits a remarkable adsorption performance for CR in solution, and its maximum adsorption amount for CR can reach up to 2512 mg g⁻¹. It shows faster adsorption and much higher adsorption capacity than the commercial AC and γ-Al₂O₃ samples under the same conditions. The studies of the kinetics and thermodynamics indicate that the adsorption of CR on the PHSCHM sample obeys the pseudo-second order model well and belongs to physisorption. The adsorption activation energy is about 7.72 kJ mol⁻¹. In view of the hierarchically meso–macroporous structure, large surface area and pore volume, the HPSCHM material could be a promising adsorbent for removal of pollutants, and it could also be used as a catalyst support.

Hierarchically porous SiO₂/C hollow microspheres (HPSCHMs) were synthesized. Its surface area is up to 1154 m² g^–1. Hierarchically porous structure facilitates diffusion of adsorbate. Its maximum adsorption amount for Congo Red is up to 2512 mg g^–1.     

Synthesis and characterization of hydroxyl-terminated butadiene-end-capped polyisobutylene and its use as a diol for polyurethane preparation

Hydroxyl-terminated telechelic polyisobutylene (PIB) was prepared through living cationic polymerization. A living PIB chain was formed using the t-Bu-m-DiCuOMe/TiCl₄ initiating system and then capped with 1,3-butadiene (BD) to prepare chlorine-terminated telechelic PIB. The chlorine-terminated telechelic PIB was then hydrolysed with tetrabutylammonium hydroxide to form hydroxyl-terminated PIB. Nuclear magnetic resonance spectroscopy confirmed hydrolysis completion. The hydroxyl-terminated PIB was subsequently used as a diol to react with 4,4-methylenebis(phenylisocyanate) (MDI) and produce a PIB-based polyurethane, which showed stronger acid resistance, hydrolysis stability and thermal oxidation stability than a commercial polyurethane.

We synthesised hydroxyl-terminated PIB through living cationic polymerisation. Then the hydroxyl-terminated PIB was subsequently used as a diol to produce a PIB-based polyurethane.     

Synergistic effects of boron-doped silicone resin and a layered double hydroxide modified with sodium dodecyl benzenesulfonate for enhancing the flame retardancy of polycarbonate

To improve the flame retardancy of polycarbonate (PC), a novel and environmentally friendly flame retardant was synthesized by combining boron-doped silicone resin (BSR) with a layered double hydroxide (LDH) modified with sodium dodecyl benzenesulfonate (SDBS) which was denoted as DBS-LDH/BSR. The structure of the hybrid was characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS), which indicated that BSR was successfully combined with DBS-LDH. X-ray diffraction (XRD) studies showed that the reaction of BSR occurred only on the surface of DBS-LDH. In addition, scanning electron microscopy (SEM) was used to further verify the combination of DBS-LDH with BSR. PC exhibited the optimum flame retardancy following the incorporation of 10 wt% DBS-LDH/BSR (5 wt% DBS-LDH and 5 wt% BSR). Based on thermogravimetric analysis, the char residue of this PC composite in air at 750 °C increased to 3.60 wt%. Mechanical test showed that the DBS-LDH/BSR could affect the mechanical properties after incorporation into PC. According to the UL-94 vertical burning test, the flame retardant rating of the PC composite improved to V-0. Furthermore, the limiting oxygen index (LOI) value of the PC composite increased to 34%. According to the cone calorimeter test, the peak heat release rate (PHRR) dramatically decreased by 44%. The morphology of the PC composite after combustion was characterized by SEM, which revealed that the pores of the composite were smaller than those of pure PC. This result was attributed to the limited spread of oxygen and heat permeation. Thus, both DBS-LDH and BSR contributed to the synergistic effects of reducing the fire hazard of PC.

Boron-doped silicone resin (BSR) combined with a layered double hydroxide (LDH) modified with sodium dodecyl benzenesulfonate (SDBS) to improve the flame retardancy of polycarbonate (PC).     

Synthesis and characterization of an α-Fe2O3/ZnTe heterostructure for photocatalytic degradation of Congo red,methyl orange and methylene blue

The leading challenge towards environmental protection is untreated textile dyes. Tailoring photocatalytic materials is one of the sustainable remediation strategies for dye treatment. Hematite (α-Fe₂O₃), due to its favorable visible light active band gap (i.e. 2.1 eV), has turned out to be a robust material of interest. However, impoverished photocatalytic efficiency of α-Fe₂O₃ is ascribable to the short life span of the charge carriers. Consequently, the former synthesized heterostructures possess low degradation efficiency. The aim of the proposed endeavor is the synthesis of a novel zinc telluride-modified hematite (α-Fe₂O₃/ZnTe) heterostructure, its characterization and demonstration of its enhanced photocatalytic response. The promising heterostructure as well as bare photocatalysts were synthesized via a hydrothermal approach. All photocatalysts were characterized by the X-ray diffraction technique (XRD), scanning electron microscopy (SEM), and electron diffraction spectroscopy (EDX). Moreover, the selectivity and activity of the photocatalyst are closely related to the alignment of its band energy levels, which were estimated by UV-Vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). Nanomaterials, specifically α-Fe₂O₃ and α-Fe₂O₃/ZnTe, were used for the degradation of Congo red (97.9%), methyl orange (84%) and methylene blue (73%) under light irradiation (>200 nm) for 60 min. The results suggested that with the aforementioned optimized fabricated heterostructure, the degradation efficiency was improved in comparison to bare hematite (α-Fe₂O₃). The key rationale towards such improved photocatalytic response is the establishment of a type-II configuration in the α-Fe₂O₃/ZnTe heterostructure.

Effective generation and transportation of electron–hole pairs in the presence of light leads to efficient degradation of textile pollutants over an α-Fe₂O₃/ZnTe nanocomposite compared to the individual components.     

Surface chemical functionality of carbon dots: influence on the structure and energy storage performance of the layered double hydroxide

As a kind of zero-dimensional material, carbon dots (CDs) have become a kind of promising novel material due to their incomparable unique physical and chemical properties. Despite the optical properties of CDs being widely studied, their surface chemical functions are rarely reported. Here we propose an interesting insight into the important role of surface chemical properties of CDs in adjusting the structure of the layered double hydroxide (LDH) and its energy storage performance. It was demonstrated that CDs with positive charge (p-CDs) not only reduce the size of the flower-like LDH through affecting the growth of LDH sheets, but also act as a structure stabilizer. After calcination, the layered double oxide (LDO) maintained the morphology of the LDH and prevented the stacking of layers. And the superiority of the composite in lithium-ion batteries (LIBs) was demonstrated. When used as an anode of LIBs, composites possess outstanding specific capacity, cycle stability and rate performance. It presents the discharge capacity of 1182 mA h g⁻¹ and capacity retention of 94% at the current density of 100 mA g⁻¹ after 100 cycles. Our work demonstrates the important chemical functions of CDs and expands their future applications.

As a kind of zero-dimensional material, carbon dots (CDs) have become a kind of promising novel material due to their incomparable unique physical and chemical properties.