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1.
Xia Liu Yuanyuan Ma Yongliang Cai Song Hu Jian Chen Zhaolin Liu Zhijuan Wang 《RSC advances》2021,11(26):15722
Bifunctional electrocatalysts with high catalytic property for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are vital for high-performance zinc–air batteries (ZnABs). In this study, an efficient bifunctional electrocatalyst with hollow structure (C–N/Co (1/2)) has been successfully prepared through carbonization of ZIF-8@ZIF-67 and evaporation of Zn ions at high temperature. With Co nanoparticles encapsulated by an N-doped porous carbon matrix, the catalyst exhibits excellent stability in aqueous alkaline solution over an extended period and good tolerance to the methanol crossover effect. The integration of an N-doped graphitic carbon outer shell and Co nanoparticles enables high ORR and OER activity, as evidenced by ZnAB using the catalyst C–N/Co (1/2) in an air cathode.An efficient bifunctional electrocatalyst with hollow structure (C–N/Co (1/2)) has been obtained through carbonization of ZIF-8@ZIF-67, which showed high ORR and OER activity, as evidenced by ZnAB using catalyst of C–N/Co (1/2) in air cathode. 相似文献
2.
Wenshu Zhou Yanyan Liu Huan Liu Dichao Wu Gaoyue Zhang Jianchun Jiang 《RSC advances》2021,11(26):15753
Developing efficient electrocatalysts for ORR/OER is the key issue for the large-scale application of rechargeable Zn–air batteries. The design of Co and N co-doped carbon matrices has become a promising strategy for the fabrication of bi-functional electrocatalysts. Herein, the surface-oxidized Co nanoparticles (NPs) encapsulated into N-doped hierarchically porous carbon materials (Co/NHPC) are designed as ORR/OER catalysts for rechargeable Zn–air batteries via dual-templating strategy and pyrolysis process containing Co2+. The fabricated electrocatalyst displays a core–shell structure with the surface-oxidized Co nanoparticles anchored on hierarchically porous carbon sheets. The carbon shells prevent Co NP cores from aggregating, ensuring excellent electrocatalytic properties for ORR with a half-wave potential of 0.82 V and a moderate OER performance. Notably, the obtained Co/NHPC as a cathode was further assembled in a zinc–air battery that delivered an open-circuit potential of 1.50 V, even superior to that of Pt/C (1.46 V vs. RHE), a low charge–discharge voltage gap, and long cycle life. All these results demonstrate that this study provides a simple, scalable, and efficient approach to fabricate cost-effective high-performance ORR/OER catalysts for rechargeable Zn–air batteries.The surface-oxidized Co nanoparticles incorporated in N-doped hierarchically porous carbon materials are designed as ORR/OER catalyst for rechargeable Zn–air batteries via dual-templating strategy and pyrolysis process. 相似文献
3.
Despite their high energy density, the poor cycling performance of lithium–oxygen (Li–O2) batteries limits their practical application. Therefore, to improve cycling performance, considerable attention has been paid to the development of an efficient electrocatalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Catalysts that can more effectively reduce the overpotential and improve the cycling performance for the OER during charging are of particular interest. In this study, porous carbon derived from protein-based tofu was investigated as a catalyst support for the oxygen electrode (O2-electrode) of Li–O2 batteries, wherein ORR and OER occur. The porous carbon was synthesized using carbonization and KOH activation, and RuO2 and Pt electrocatalysts were introduced to improve the electrical conductivity and catalytic performance. The well-dispersed Pt/RuO2 electrocatalysts on the porous N-doped carbon support (Pt/RuO2@ACT) showed excellent ORR and OER catalytic activity. When incorporated into a Li–O2 battery, the Pt/RuO2@ACT O2-electrode exhibited a high specific discharge capacity (5724.1 mA h g−1 at 100 mA g−1), a low discharge–charge voltage gap (0.64 V at 2000 mA h g−1), and excellent cycling stability (43 cycles with a limit capacity of 1000 mA h g−1). We believe that the excellent performance of the Pt/RuO2@ACT electrocatalyst is promising for accelerating the commercialization of Li–O2 batteries.The excellent performance of the Pt/RuO2@ACT electrocatalyst is promising for accelerating the commercialization of Li–O2 batteries. 相似文献
4.
Li-Juan Peng Jie-Ping Huang Qiu-Ren Pan Ying Liang Na Yin Hang-Chang Xu Nan Li 《RSC advances》2021,11(32):19406
Developing a low-cost, simple, and efficient method to prepare excellent bifunctional electrocatalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical in rechargeable zinc–air batteries. Non-stoichiometric M0.85Se (M = Ni or Co) nanoparticles are synthesized and modified on nitrogen-doped hollow carbon sphere (NHCS). The NHCS loaded Ni0.85Se (Ni0.85Se-NHCS) with rich Ni3+ presents higher OER activity, whereas the NHCS-loaded Co0.85Se (Co0.85Se-NHCS) with abundant Co2+ displays better ORR activity, respectively. When Co0.85Se-NHCS is mixed with Ni0.85Se-NHCS in a mass ratio of 1 : 1, the resulting mixture (Ni0.85Se/Co0.85Se-NHCS-2) shows better ORR and OER dual catalytic functions than a single selenide. Moreover, zinc–air batteries equipped with Ni0.85Se/Co0.85Se-NHCS-2 as the oxygen electrode catalyst exhibit excellent charge and discharge performance as well as improved stability over precious metals. This work has developed a simple and effective method to prepare excellent bifunctional electrocatalysts for ORR and OER, which is beneficial for the practical large-scale application of zinc–air batteries.The mixture Ni0.85Se/Co0.85Se-NHCS-2 displayed superior electrocatalytic performance to that of Ni0.85Se-NHCS or Co0.85Se-NHCS alone. This provided a simple approach to develop ORR/OER bifunctional electrocatalysts for zinc–air batteries. 相似文献
5.
Naohito Yamada Damian Kowalski Akira Koyama Chunyu Zhu Yoshitaka Aoki Hiroki Habazaki 《RSC advances》2019,9(7):3726
In this study, platelet-type carbon nanofibers prepared by the liquid phase carbonization of polymers in the pores of a porous anodic alumina template were used to prepare the Co3O4/carbon electrocatalysts. For comparison, Co3O4 nanoparticles were also deposited on multiwall carbon nanotubes (MWCNTs). Both the nitrogen-free platelet-type carbon nanofibers (pCNFs) and the nitrogen-containing analogue (N-pCNFs) exhibited better dispersion and higher amount of deposited Co3O4 nanoparticles compared to the MWCNTs. In addition, many individual Co3O4 nanoparticles were deposited separately on pCNF and N-pCNF, whereas aggregated deposition was commonplace on MWCNTs. The results indicated that the side wall of the pCNFs, which consisted of carbon edge planes, was the preferential nucleation site of Co3O4 nanoparticles rather than the basal planes of carbon that predominated the surface of the MWCNTs. The oxygen reduction reaction (ORR) activity of the Co3O4/pCNF composite in 0.1 mol dm−3 KOH solution was better than that of Co3O4/MWCNTs. The N-pCNF further enhanced the ORR activity of the Co3O4/pCNFs even though the dispersion and supported amount of Co3O4 nanoparticles were negligibly affected by the presence of the nitrogen species. Synergistic interactions of the Co3O4 nanoparticles with N-doped CNFs contributed to the increased ORR activity.In this study, platelet-type carbon nanofibers prepared by the liquid phase carbonization of polymers in the pores of a porous anodic alumina template were used to prepare the Co3O4/carbon electrocatalysts. 相似文献
6.
The development of efficient, cost-effective and stable N-doped carbon material with catalytic activity as an excellent catalyst for the oxygen evolution reaction (OER) is critical for renewable energy systems. In this study, the unique tip-half-closed N-doped carbon nanohorns (THC-N-CNHs) were firstly produced by the positive pressure-assisted arc discharge method using N2 as the nitrogen source. Benefitting from the novel tip-half-closed structure and sufficient porosity, the specific surface area (SSA) of THC-N-CNHs is calculated to be 670 m2 g−1 without any further treatment, which is three times larger than that of traditional tip-closed CNHs. More importantly, the content of nitrogen can achieve ∼1.98 at% with noticeable pyridinic-N enrichment, increasing the number of active sites for the OER. Furthermore, the three-dimensional spherical feature and the unique pore structure for THC-N-CNHs lead to the fast transportation of electrons, and facile release of the evolved O2 bubbles during the OER process. Therefore, THC-N-CNHs exhibit excellent electrocatalytic activity toward the OER, with an overpotential of 328 mV at 10 mA cm−2, which is superior to that of most N-doped carbon material-based electrocatalysts. Meanwhile, the resulting catalyst also shows excellent durability after long-term cycling. Finally, we emphasize that THC-N-CNHs can be promising candidates as cheap, industrially scalable catalytic scaffolds for OER application.The unique tip-half-closed N-doped carbon nanohorns were firstly produced with sufficient porosity and noticeable pyridinic-N, exhibiting excellent OER performance. 相似文献
7.
The design of stable and high performance metal free bifunctional electrocatalysts is a necessity in alkaline zinc–air batteries for oxygen reduction and evolution reaction. In the present work co-doped carbon materials have been developed from polymeric precursors with abundant active sites to achieve bifunctional activity. A 3-dimensional microporous nitrogen–carbon (NC) and co-doped nitrogen–sulfur–carbon (NSC) and nitrogen–phosphorus–carbon (NPC) were synthesized using poly(2,5-benzimidazole) as an N containing precursor. The obtained sheet like structure shows outstanding ORR and OER performance in alkaline systems with excellent stability compared to Pt/C catalyst. The doped heteroatom in the carbon is expected to have redistributed the charge around heteroatom dopants lowering the ORR potential and modifying the oxygen chemisorption mode thereby weakening the O–O bonding and improving the ORR activity and overall catalytic performance. The bifunctional activity (ΔE = Ej=10 − E1/2) of an air electrode for NPC, NSC, NC and Pt/C is 0.82 V, 0.87 V, 1.06 V and 1.03 V respectively, and the NPC value is smaller than most of the reported metal and non-metal based electrocatalysts. The ORR (from onset potential) and OER (10 mA cm−2) overpotential for NPC, NSC, and NC is (290 mV, 410 mV), (310 mV, 450 mV) and (340 mV, 600 mV) respectively. In the prepared catalyst the NPC exhibited higher ORR and OER activity (NPC > NSC > NC). The doping of P in NPC is found to have a great influence on the microstructure and therefore on the ORR and OER activity.Metal free bifunctional catalysts based on co-doped carbon materials synthesized from polymeric precursors via a simple pyrolysis route with high cyclic stability and low polarization for Zn–air batteries. 相似文献
8.
Hanzeng Zou Supeng Pei Zongshang Zhou Zhaoyan Chen Xia Xiong Yueyang Sun Yongming Zhang 《RSC advances》2020,10(2):779
Electrocatalysts for the oxygen reduction reaction (ORR) are crucial in metal–air batteries, fuel cells and other electrochemical devices. In this study, iron and nitrogen co-doped carbon sphere electrocatalysts were synthesized by electrospinning and thermal treatment. According to the results, the catalyst marked as Fe–N/MCS-181 (Fe, N-doped mesoporous carbon spheres, iron nitrate nonahydrate as the iron source) has not only the highest iron content, which reaches up to 0.13%, but also a spherical shape. And its pore sizes are 11 and 35 nm. For the electrochemical performance, the onset potential (Eonset) of Fe–N/MCS-181 is −0.018 V, while the half-wave potential (E1/2) of Fe–N/MCS-181 is −0.145 V, which is better than the commercial Pt/C catalyst (E1/2 is −0.18 V). The durability of the Fe–N/MCS-181 catalyst is better than commercial Pt/C. After 10 000 s, the retention ratio of current density is 86.4%, while that of the commercial Pt/C catalyst is 84.2%. At the same time, the methanol tolerance of the Fe–N/MCS-181 catalyst is also excellent. After adding methanol, the current density of the Fe–N/MCS-181 catalyst has no obvious change. This study provides an easy method to fabricate a highly efficient and durable Fe, N-doped carbon catalyst for the oxygen reduction reaction.Fe, N-doped carbon spheres as high-efficiency ORR catalysts were prepared by a facile electrospinning process. 相似文献
9.
Catalysts used for the oxygen reduction reaction (ORR) are crucial to fuel cells. However, the development of novel catalysts possessing high activity at a low cost is very challenging. Recently, extensive research has indicated that nitrogen-doped carbon materials, which include nonprecious metals as well as metal-based oxides, can be used as excellent candidates for the ORR. Here, Co/Co3O4@N-doped carbon (NC) with a low cost and highly stable performance is utilized as an ORR electrocatalyst through the pyrolysis of an easily prepared physical mixture containing a cobalt-based zeolite imidazolate framework (ZIF-67 precursor) and biomass materials from poplar flowers. Compared with the pure ZIF-derived counterpart (Co@NC) and PL-bio-C, the as-synthesized electrocatalysts show significantly enhanced ORR activities. The essential roles of doped atoms (ZIF-67 precursor) in improving the ORR activities are discussed. Depending mainly on the formation of Co–Co3O4 active sites and abundant nitrogen-containing groups, the resulting Co/Co3O4@NC catalyst exhibits good electroactivity (onset and half-wave potentials: Eonset = 0.94 V and E1/2 = 0.85 V, respectively, and a small Tafel slope of 90 mV dec−1) compared to Co@NC and PL-bio-C and follows the 4-electron pathway with good stability and methanol resistance. The results of this study provide a reference for exploring cobalt-based N-doped biomass carbon for energy conversion and storage applications.Co/Co3O4@NC catalyst for the ORR with a low cost and highly stable performance is developed through the pyrolysis of an easy physical mixture containing ZIF-67 as the precursor and poplar flowers as the carbon source. 相似文献
10.
Zhengmei Zhang Jingyan Zhang Tao Wang Zhiwei Li Guijin Yang Haiqin Bian Jinyun Li Daqiang Gao 《RSC advances》2018,8(10):5338
One dimensional spinel CoFe2O4 nanofibers were synthesized via the electrospinning technique. The nanofibers were calcined at different temperatures. All CoFe2O4 nanofibers show excellent oxygen evolution reaction (OER) performance. The nanofibers calcined at 750 °C have a multi-particle nanochain structure. The nanochain exhibits excellent catalytic performance for OER in 1 M KOH (pH = 14) producing a current density of 10 mA cm−2 at an overpotential of 0.34 V, and the small onset potential of 1.32 V versus RHE, better than that of the commercial Ir/C (20%) catalyst. Furthermore, the stability of CoFe2O4 multi-particle nanochains toward the OER decreases by only 0.78% even after a long period of 80 000 s. Our finding suggests that CoFe2O4 nanofibers with a multi-particle nanochain structure could serve as a new group of OER electrocatalysts with excellent performance.One dimensional spinel CoFe2O4 nanofibers were synthesized via the electrospinning technique. 相似文献
11.
Xing Yang Xianghua Wu Zeping Guo Qingyu Li Hongqiang Wang Chujun Ke Wei Zeng Xiafei Qiu Yun He Xiaoguang Liang Yoonseob Kim 《RSC advances》2020,10(55):33327
With the merits of high safety and energy density, all-solid-state zinc–air batteries possess potential applications in flexible and wearable electronic devices. Especially, the air cathodes with bifunctional catalytic activity, i.e. oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been received enormous attention. In this work, we provide a novel phosphorus/nitrogen co-doped and bimetallic metal–organic framework (MOF)-derived cathode configurated with phosphorus-doped bimetallic FeNi alloys and a nitrogen-doped porous carbon layer loaded on graphene (P–FeNi/NC@G). The P–FeNi/NC@G electrode exhibits a superior OER activity with an overpotential of 310 mV at 10 mA cm−2 and an ORR performance with a half-wave potential of 0.81 V. With P–FeNi/NC@G as the air cathode, the integrated all-solid-state rechargeable zinc–air battery presents a high open-circuit voltage of 1.53 V, a high peak power density of 159 mW cm−2, a small charge–discharge voltage gap of 0.73 V at 5 mA cm−2, as well as excellent long-term stability up to 144 cycles. This work not only expands the air cathode materials database but also develops a new co-doped synthesis method that can be utilized to fabricate a cathode with promoted catalytic efficiency, resulting in improved performance for an all-solid-state zinc–air battery.The bimetallic FeNi-MOFs are employed to fabricate P–FeNi and N–carbon co-doped bifunctional catalyst. Due to the enhanced catalytic performance, the peak power density of all-solid-state zinc–air battery is 159 mW cm−2. 相似文献
12.
Jingjing Feng Yu Meng Zixuan Lian Liang Fang Ziyao Long Yongtao Li Yun Song 《RSC advances》2019,9(17):9729
Developing cheap and efficient transition metal-based catalysts for the oxygen evolution reaction (OER) plays the key role in large-scale implementation of hydrogen production. However, there is still a lack of effective ways to tune the catalysts performance for the OER reaction from the aspect of structure design and element modulation simultaneously. Herein, a novel Cu0.33Co0.67S2 hexagonal nanosheet has been synthesized through the coprecipitation reaction followed by subsequent vapor sulfidation. Simply mixed with carbon nanotubes (CNTs) during electrode preparation, this Cu0.33Co0.67S2 exhibits an overpotential of 284 mV vs. RHE at a current density of 10 mA cm−2 in 1.0 M KOH. The improved OER performance of the Cu0.33Co0.67S2 electrode can be attributed to the electrocatalytically active sites involved in octahedral coordination structures and further activated by Cu substitution. The encouraging results provide insight into further rational design of transition metal-based electrochemical catalysts towards OER applications.Developing cheap and efficient transition metal-based catalysts for the oxygen evolution reaction (OER) plays the key role in large-scale implementation of hydrogen production. 相似文献
13.
Renewable energy technology development focuses on the exploration of economical and efficient non-precious metal catalysts to replace precious metal catalysts in electrocatalytic reactions including oxygen reduction (ORR) and hydrogen evolution (HER). Herein, we synthesized a cobalt single atom catalyst anchored on a N-doped carbon framework by a doping-adsorption-pyrolysis strategy. The optimized Co SAs/CN-3 catalyst showed excellent HER and ORR bifunctional electrocatalytic performance, which could be attributed to the highly dispersed Co–N4 active sites, large specific surface area and abundant pore structure. Density functional theory shows that the isolated active Co–N4 site shows low hydrogen adsorption Gibbs free energy, and promotes the adsorption of H and oxygen-containing intermediates in HER and ORR. This work not only provides a new idea for the construction of transition metal catalysts with atomic accuracy but also provides powerful guidance for the development of efficient bifunctional electrocatalysts.Atomically dispersed Co–N4 sites anchored on a N-doped carbon framework catalyst were constructed by a novel doping-adsorption-pyrolysis strategy for bifunctional electrocatalytic HER and ORR. 相似文献
14.
Mayilvel Dinesh Meganathan Taizhong Huang Hengyi Fang Jianfeng Mao Guoxin Sun 《RSC advances》2019,9(5):2599
Non-noble metal-based catalysts with efficient catalytic activities for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are critical for energy conversion devices, including fuel cells and metal–air batteries. In this work, novel hafnium phosphide-reduced graphene oxide nanosheets (HfP-rGO NS) and hafnium disulfide-reduced graphene oxide nanosheets (HfS2-rGO NS) were synthesized and investigated as bifunctional electrocatalysts for OER and ORR. The prepared HfP-rGO NS and HfS2-rGO NS catalysts showed nanosheet structures, where the HfP or HfS2 nanosheet was closely packed with rGO. A unique methodology was adopted to lodge the non-metal oxide catalytic sheets (i.e., HfP and HfS2) over the rGO sheets, which positioned the oxide layer on the catalytic sheet surface for instant oxygen evolution. Low intensity X-ray diffraction patterns and Raman spectra confirmed the sheet-like structure of HfP-rGO NS and HfS2-rGO NS. Scanning electron microscope mapping images revealed that all elements (i.e., Hf, P, C and O for HfP-rGO NS and Hf, S, C and O for HfS2-rGO NS) were equally distributed in the synthesized heteroatomic nanosheets. Moreover, both the HfP-rGO NS and HfS2-rGO NS demonstrated excellent durability for both ORR and OER. This outperforms the most state-of-the-art non-precious-metal-based bifunctional catalysts, which is attributed to the synergistic effect of rGO and Hf-based catalysts. The different ORR and OER reaction potentials in HfP-rGO NS and HfS2-rGO NS likely result from the influence of HfP and HfS2.Sheet-like structured hafnium phosphide (HfP) and hafnium disulphide (HfS2) catalysts show high catalytic activity for both oxygen evolution and oxygen reduction reactions, which are determined by the compositional anion ions. 相似文献
15.
Wenjian Zou Kunpeng Dou Qi Jiang Jiadong Xiang Chao-Cheng Kaun Hao Tang 《RSC advances》2019,9(68):39951
Developing active multifunctional electrocatalysts composed of earth-abundant and cheap elements is an urgent demand in energy conversion applications. This study presents a facile approach for the scalable synthesis of nanostructured cobalt phosphide embedded in carbon nanosheets (CoP NPs/CNSs). The hybrid structures show highly efficient trifunctional electrocatalytic activities toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) under alkaline condition. The catalytic performances, which are remarkably superior to those of the previously reported CoP nanostructures enclosed by single or a few low index facets, can be attributed to the nearly spherical shape of the CoP nanoparticles with many more exposed crystal planes. Density functional theory (DFT) computations are performed to investigate the facet effects of CoP on electrocatalytic activity, and they reveal the relatively low overpotentials of (101) facets towards the OER and the free energy of water dissociation (ΔGH2O) and adsorbed H intermediates (ΔGH*) of (311) toward the HER being close to thermoneutral. This work is expected to inspire the design and fabrication of multifunctional and high-efficiency electrocatalysts by selectively exposing specific crystal planes.The CoP nanoparticles/carbon sheets hybrid structures are highly efficient trifunctional electrocatalytic activities toward the oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction under alkaline condition. 相似文献
16.
Production of bifunctional catalysts for catalyzing both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly advisable but challenging with respect to the applications of these catalysts in renewable energy conversion and storage technologies. Herein, we prepared highly reactive and stable cobalt-embedded nitrogen-rich carbon nanosheets (Co–N/CNs). Based on density functional theory (DFT) calculations and experiments, the as-prepared Co–N/CNs showed outstanding catalytic activities toward both OER and ORR. The optimized Co–N/CNs-800 catalyst revealed outstanding bifunctional catalytic activities for both ORR and OER with high catalytic efficiency and long-term durability, which were even comparable with those of the state-of-the-art Pt/C and RuO2 catalysts. Furthermore, we observed that different cobalt salt precursors affected the size of Co nanoparticles, and both ORR and OER catalytic activities displayed completely consistent variations (sulfate < acetate < chloride < nitrate). An all-solid-state Al–air battery device comprising this hybrid catalyst showed superior performance when compared with the device containing the Pt/C catalyst.Production of bifunctional catalysts for catalyzing both ORR and OER is highly advisable but challenging with respect to the applications of these catalysts in renewable energy conversion and storage technologies. 相似文献
17.
Qing Zhang Wenjie Han Zhixiao Xu Yinling Li Lu Chen Zhengyu Bai Lin Yang Xiaolei Wang 《RSC advances》2020,10(46):27788
With the aggravation of the energy crisis, increasing attention has been paid to electrocatalytic technology for renewable energy devices. In particular, the research on catalysts towards the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) has become more urgent, and the development of multifunctional electrocatalysts has become a research trend. Here we report the synthesis of waxberry-like cobalt–nickel oxide/S,N-codoped carbon hollow nanocomposites as trifunctional catalysts. Uniform cobalt–nickel glycerate solid spheres are first synthesized as the precursor and subsequently chemically transformed into cobalt–nickel oxide/S,N-codoped carbon hollow nanospheres. Benefiting from the synergistic coupling of cobalt–nickel oxide and S,N-codoped carbon nanocomposites, hierarchical porosity and hollow structure, the cobalt–nickel oxide/S,N-codoped carbon nanohybrids exhibit superior trifunctional electrocatalytic activity and durability towards OER, ORR, and HER in alkaline media.The catalyst is assembled from small nanoparticles in the shape of a bayberry, and exhibits superior trifunctional electrocatalytic activity. 相似文献
18.
The development of high-performance catalysts for oxygen-evolution reaction (OER) is paramount for cost-effective conversion of renewable electricity to fuels and chemicals. Here we report, highly efficient, ultra-durable and earth-abundant Ni@Fe-NP electrocatalysts developed by solvothermal method for oxygen evolution reaction (OER). The newly developed oxygen electrode show prolonged stability and high catalytic-activity in line with water oxidation keeping alkaline condition which requires overpotential of only 211 mV at current density of 10 mA cm−2. Collectively, the as-prepared amorphous Ni@Fe-NP rippled nanostructured electrode is the most effective oxygen evolution electrode in alkaline solution. Therefore, this study will offer exciting new avenues for designing self-supported electrode materials towards water splitting and other applications.The development of high-performance catalysts for oxygen-evolution reaction (OER) is paramount for cost-effective conversion of renewable electricity to fuels and chemicals. 相似文献
19.
Rakesh Mondal Himanshu Ratnawat Sarvesh Kumar Anil Kumar Preetam Singh 《RSC advances》2020,10(30):17845
The oxygen evolution reaction (OER) is a key half-reaction in hydrogen–oxygen electrolysers that is very important for efficient electrochemical energy generation, storage and fuel production that offers a clean alternative to fissile fuel combustion based energy systems. Several transition metal containing perovskites were recently explored for the development of superior OER catalysts, and their activity was correlated with the applied potentials at a specific current density to eg electron density present in the materials. The rock salt structure is envisaged here as a model host structure similar to perovskite to tune the eg electrons to obtain superior electro-catalytic activity. Incorporation of Ni into CoO lattices helps to stabilize the rock salt structure and modulate the eg electrons to develop superior OER and ORR electrocatalysts. Nickel doped rock salt structured CoO, NixCo1−xO (0 ≤ x ≤ 0.5), were synthesized by employing a solid state metathesis synthesis route. The compounds were characterised by powder X-ray diffraction (XRD), TGA, FT-IR and X-ray Photoelectron Spectroscopy (XPS). Ni0.3Co0.7O with 1.3 eg electrons showed superior electrocatalytic activity for the oxygen evolution reaction. The overpotential for the Ni0.3Co0.7O sample was also found to be ∼0.450 V for 1 M and about ∼0.389 V at 5 M concentration of the KOH electrolyte.Incorporation of Ni into CoO lattices helps to stabilize the rock salt structure and modulate the eg electrons to develop superior OER and ORR electrocatalysts. 相似文献
20.
Hong Jin Yongping Luo Laihong Zhou Zonghu Xiao Fayun Zhang Ping Huang Chen Liu 《RSC advances》2022,12(21):13440
The development of high efficiency and low-cost electrocatalysts for the oxygen reduction reaction (ORR) is urgently desired for many energy storage and conversion systems. Nitrogen-doped carbon xerogels (NCXs) which have been successfully applied as effective electrocatalysts for the ORR have continued to attract attention due to their competitive price and tunable surface chemistry. A new dual N-doped NCX (NCoNC) electrocatalyst is fabricated as a carbon based catalyst though a facile impregnation of peptone in a precursor and ammonia etching pyrolysis method. XPS analysis demonstrates that the NCoNC electrocatalyst not only has a high N doping amount, but also has an optimized chemical state composition of N doping, which play an important role in improving the microstructure and catalytic performance of the catalysts. XRD and HRTEM results show that the doped metal nano-particles are coated with a double carbon layer of graphene carbon (inner layer) and amorphous carbon (outer layer) forming serrated edges that facilitate the ORR process. The as-obtained NCoNC catalyst exhibits good electrocatalytic performance and excellent stability for the ORR in both acidic and alkaline environments. In particular, in alkaline electrolyte, the decrements of both the limiting current density and the half-wave potential of the NCoNC catalyst were significantly lower than those of a commercial Pt/C catalyst during accelerated aging tests. When serving as an air electrode in Zn–air batteries, the catalyst also exhibits superior catalytic performance with a peak power density of 78.2 mW cm−2 and a stable open-circuit voltage of 1.37–1.43 V. This work presents a novel tactic to regulate the microstructure and composition of carbon-based electrocatalysts by the facile and scalable dual-effect nitrogen doping method which may be conducive to promoting and developing highly efficient and promising electrocatalysts for the ORR.This work presents a novel tactic to regulate the microstructure and composition of carbon-based catalysts by the facile and scalable dual-effect nitrogen doping method which may be conducive to promoting highly efficient electrocatalysts for ORR. 相似文献