ELECTROCHIMICA ACTA
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2022
·
IF 7.336
Peiyun Zhou,Rushuo Li,Junjun Lv,Xiubing Huang,Yunfeng Lu,Ge Wang
Transition metal phosphides have been regarded as excellent electrocatalysts for hydrogen evolution reaction (HER), and the morphological engineering on them is one of the most effective methods to boost their HER activity. Here, the morphology of CoP nanoarrays supported on the nickel foam (NF) is controlled by morphological engineering using sodium edetate (EDTA·4Na) as a regulating factor. Through the hydrothermal-phosphating process, a self-supported electrode (NF/Ni 2 P/CoP-NS) with a tertiary structure of NF, Ni 2 P layer and CoP nanosheets is obtained. Due to the abundant exposed active sites, as well as superior conductivity and mass transfer capabilities of the nanosheets, NF/Ni 2 P/CoP-NS exhibits excellent hydrogen evolution reaction activity in 1.0 M KOH. It merely needs an overpotential of 64 mV to supply the current density of 10 mA cm −2 , far better than the 90 mV of NF/Ni 2 P/CoP-NN with a nanoneedle-like morphology. The morphological engineering of introducing modifiers (such as EDTA·4Na) to control ionic coordination is expected to develop diverse two-dimensional materials for catalysis and energy storage.
研究领域:
材料科学
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电化学
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能源存储与转换
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
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2022
·Vol. 132
·期 18
·
IF 2.877
Zheng Xiaochun,Ren Shoutian,Gai Qixiao,Wang Yidi,Liu Wenjun
Various defects of nanocomposites inevitably bring some harmful effects on their photoelectric performance, especially considering that interface defects seriously hinder the carrier interfacial transfer. Here, the interface optimization can be realized between graphitic carbon nitride (C 3 N 4 ) and CoP co-catalyst by the introduction of good conductive carbon nanosheets (CNs). As a result, the defect density of synthesized C 3 N 4 /CNs/CoP is reduced to 1.40 × 10 12 cm −3 from 2.55 × 10 12 cm −3 of C 3 N 4 /CoP, and its interface impedance is correspondingly reduced to 34% of that of C 3 N 4 /CoP. Therefore, the optimal H 2 evolution rate of 5.26 mmol g −1 h −1 and apparent quantum efficiency of 9.27% at 420 nm are realized, which are 4.8 and 8.1 times that of C 3 N 4 /CoP photocatalyst in the absence of CNs, respectively. This work provides a general solution to reduce defect density and carrier transfer resistance in nanocomposites by the introduction of a highly conductive buffer layer.
研究领域:
材料科学
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光催化
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能源科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2019
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IF 4.175
Peng Hei,Chaozhu Shu,Zhiqian Hou,Ruixin Zheng,Tingshuai Yang,Minglu Li,Zhiqun Ran,Yue Wang,Dexin Mei,Jianping Long
In this work, we fabricated a novel free-standing Fe doped CoP nanowire on carbon cloth (Fe–CoP/CC) electrode with high catalytic activity for Li–O 2 batteries. It is unexpected that the Li–O 2 battery with Fe–CoP/CC electrode demonstrated a low potential of 0.8 V and exceptional cycle stability of more than 500 cycles with no significant voltage attenuation compared with previously reported counterparts. Such excellent performance can be partly attributed to its fine nanowire structure and its large specific surface area (419.14 m 2 g −1 ). Furthermore, iron doping plays a crucial role in improvement of battery performance because the doped Fe can modulate the internal electronic structure and optimize the absorption of intermediate products, which have been proved to be the determinant for optimizing the catalytic activity. Thus, it is believed that heterogeneous element doping in binary or ternary metal compounds is a promising strategy to fabricate high performance oxygen electrode materials for Li–O 2 batteries in the next few years.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Guilin Li,Lei Li,Zhan Lin
Electrocatalytic water splitting, as an ideal technology in renewable energy applications , suffers from high electrical energy consumption due to the slow kinetics of HER and OER reactions. Therefore, it is urgent to design efficient bifunctional catalysts to improve the reaction kinetics. Herein, a self-supported electrode, anchoring CoP nanoparticles on N-doped carbon/graphene (NC-G) and chemically growing on Ni foam as a whole electrode (denoted as NC-G-CoP/NF) displays promising electrocatalytic performance in 1.0 M KOH electrolyte, with a low overpotentials of 68 mV at 10 mA cm −2 for HER and 255 mV at 50 mA cm −2 for OER. This bifunctional electrocatalyst only needs 1.435 V to generate 10 mA cm −2 for overall water splitting. The outstanding electrocatalytic performance is ascribed to the following factors: i) inherent nature of transition metal phosphides, ii) abundant and high dispersion N active sites in NC-G, iii) strong interaction between the NC-G and CoP nanoparticles, and iv) rapid electron transfer between the catalytic centers and Nickle foam. This provides a new perspective to design efficient electrocatalysts for electrocatalytic water splitting.
研究领域:
材料科学
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可再生能源
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2021
·Vol. 13
·期 47
·20281-20288
·
IF 7.79
Xintong Li,Yizhe Liu,Qidi Sun,Wei-Hsiang Huang,Zilong Wang,Chu-Chen Chueh,Chi-Liang Chen,Zonglong Zhu
In the electrochemical water splitting process, integrating hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the same electrolyte with the same catalyst is highly beneficial for increasing the energy efficiency and reducing the fabrication cost. However, most OER catalysts are unstable in the acidic solution, while HER shows poor kinetics in the alkaline solution, which hinders the scale-up application of electro-catalytic water splitting. In this work, a CoP/Co3O4 heterostructure is firstly fabricated and then O and P defects are introduced via surface engineering (s-CoP/Co3O4). The as-prepared material was employed as the catalyst towards electrochemical water splitting in an alkaline environment. In alkaline HER, a current density of −10 mA cm−2 can be achieved at an overpotential of 106 mV vs. RHE. In the OER process, the overpotential of s-CoP/Co3O4 electrode is only 211 mV vs. RHE at 10 mA cm−2 in 1 M KOH, and the corresponding Tafel slope is only 58.4 mV dec−1 so that the s-CoP/Co3O4 electrode could be used as the bifunctional catalyst for alkaline water splitting. This work provides a simple and low-cost approach to fabricate a Co-based heterojunction electrode with unsaturated metal sites to improve the electro-catalytic activities towards water splitting.
研究领域:
材料科学
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电化学
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催化科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
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IF 5.3
Balaji Panchal,Yuzhuang Sun,Cunliang Zhao,Bangjun Liu,Kai Bian,Jinxi Wang,Qiaojing Zhao
Declining fossil fuel reserves and fluctuating petroleum prices have prompted global research efforts to develop clean, renewable, and sustainable alternatives to traditional fossil fuels. In this study, a reusable and eco-friendly activation catalyst was designed by combining KOH with a polymer. A series of three polymer catalysts were synthesized, and their catalytic activities were compared with those of COP-KOH, COP-K 3 PO 4 and COP-KF. It was found that the prepared COP-KOH catalyst showed the highest activity. The catalyst was characterized by FT-IR, which confirmed the presence of potassium support successfully coordinated on the COP. Additional analyses included N 2 and BET, XPS, SEM, mapping, and basicity measurement by ICP analysis. The prepared catalysts a possessed mesoporous structure, high surface area of 4.2961 m 2 /g −1 , pore volume of 2.2439 m 2 /g −1 , and high basicity. Here, the activity and stability of the potassium modified mesoporous polymer COP-KOH catalyst in green fuel synthesis from waste fried sunflower oil was evaluated. The green fuel conversion rate of 96.42 % was achieved under optimal reaction conditions, with a molar ratio of 6:1 methanol to fried sunflower oil, a catalyst concentration of 85 wt%, a reaction temperature of 61 °C, and a reaction time of 4.5 h. A satisfactory yield of 92.1 % was obtained after use for four consecutive cycles without significant deactivation, and after the fourth cycle catalyst was reactivated with KOH. The characteristic differences in the FT-IR results of the fresh catalyst, used catalyst, and re-activated COP-KOH catalyst, indicated the mode of interaction between the catalyst and reactants. The kinetics of the transesterification reaction was also determined, and the activation energy was found to range from 20.9 to 23.4 kJ . mol −1 . The properties of the green fuel were found to be in good agreement with the ASTM D6571-02 standard. The catalyst is recyclable, and using inexpensive feedstock makes the overall process more cost-effective and environmentally friendly.
研究领域:
化学工程
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环境科学
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能源科学
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产品关联
DOI
高影响因子
ACS Omega
·
2018
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IF 0
Yong Xu,Yong Chen,Wen-Fu Fu
CoP was synthesized in situ on the surface of CdS nanowires using a cobalt–ammine complex as a precursor. The generated CoP@CdS photocatalyst was well characterized by X-ray diffraction, transmission electron microscopy, selected-area electron diffraction, and diffuse reflectance spectra. A more efficient charge transfer was successfully achieved owing to the close contact between CoP and CdS. The hybrid photocatalyst showed excellent activity for the reduction of nitroarenes to the corresponding anilines or azobenzene compounds in water. In present work, hydrogen evolution and nitro reduction were concurrent and with the consumption of substrate, the rate of hydrogen evolution increased. The driving force for the reduction originated from the activated hydrogen species in the photocatalytic reaction rather than from dihydrogen. The photocatalytic activity of as-prepared CoP@CdS in situ is comparable to that of the catalysts formed using a noble metal loaded onto CdS. Mechanistic investigation showed that the condensation route is the major pathway for nitro reduction in the present system, and azo compounds could be obtained with less irradiation time, while aniline will be obtained via long-time irradiation.
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
CRYSTENGCOMM
·
2022
·Vol. 24
·期 28
·5141-5148
·
IF 3.756
Yan Ma,Dianjun Chi,Yuping Tao,Shengjun Liu,Lei Dong,Yu Chen,Lifang He,Kui Zhang
Catalysts with low cost, high efficiency, and no need for precious metal cocatalysts are the key to realizing the maximum utilization of solar energy-efficient hydrogen (H2) production. In this study, a series of graphitic carbon nitride-derived catalysts (g-C3N4/CoP@C) were successfully obtained by in situ phosphating of g-C3N4/Co-BDC. A CoP@C cocatalyst developed with Co-BDC nanosheets as precursors can accelerate the H2 generation of g-C3N4. The close interface between CoP@C and g-C3N4 increased the electron–hole separation efficiency. Moreover, the CoP@C surface carbon accelerated electron transfer and increased the light absorption range. The prepared g-C3N4/CoP@C composite material exhibited H2 production capability up to 1968 μmol g−1 (3 h), approximately 129.9 times that of g-C3N4. Therefore, the CoP@C cocatalyst is proposed as an alternative to non-precious metal cocatalysts based on the findings of the study.
研究领域:
材料科学
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能源化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Lili Zhang,Yuanting Lei,Wenjing Xu,Dan Wang,Yafei Zhao,Wenxing Chen,Xu Xiang,Xinchang Pang,Bing Zhang,Huishan Shang
Developing high-efficiency, low-cost, and durable bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is greatly desirable and challenging. Herein, a highly active and durable nitrogen-doped CoP coupled CeO 2 nanowire heterostructure ( N -CoP/CeO 2 ) electrocatalyst is prepared on carbon cloth. The resultant N -CoP/CeO 2 exhibits superb catalytic activities for OER and HER, featuring low overpotentials of 215 and 74 mV at 10 mA cm −2 in 1.0 M KOH. The N -CoP/CeO 2 assembled water electrolyzer has super stability, which needs relatively low cell voltages of 1.52 V@10 mA cm −2 over 42 days (≈95.9 % retention) and 1.80 V@400 mA cm −2 over 21 days (≈94.4 % retention), outperforming most reported cost-effective electrocatalysts. Theoretical calculations reveal that the metallic heterostructure interfaces of N -CoP/CeO 2 possess a fast electron transfer pathway, optimized adsorption/desorption process of reactive intermediates, and reduced reaction energetic barriers, thus enhancing the electrocatalytic activity. Additionally, the robust three-dimensional configuration and the oxygen vacancies-rich CeO 2 component in N -CoP/CeO 2 are regarded as significant contributors to improving stability and promoting long-term durability.
研究领域:
材料科学
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电化学
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能源催化
✓ 已验证
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2022
·
IF 6.465
Zhenghao Jin,Shuhong Li,Runfa Zhou,Mengkai Xu,Weixue Jiang,Kai Du
Adding nanoparticles can enhance the mass and heat transfer of basic fluid, improving the coefficient of performance(COP) of the absorption refrigeration system(ARS). However, there are few experimental studies on the effects of absorption pressure and temperature on the absorption performance of nanofluid in an actual ARS. Therefore, the TiO 2 nanoparticles are added to the NH 3 - H 2 O – LiBr working fluid. The difference in ammonia mass fraction between the inlet and outlet solution of the absorber (Δ ε ' a ) is compared with when the solution is absorbed saturated (Δ ε a ). The results indicate that the Δ ε ' a and system COP increase when the absorption temperature decreases, the absorption pressure increases, or the TiO 2 mass fraction increases. The ratio Δ ε ' a /Δ ε a is used to evaluate the absorption efficiency of the nanofluid. The positive effects of nanofluid on the absorption efficiency and COP slightly increase when absorption temperature increases, but decrease when the absorption pressure is greater than 0.31 MPa. For all of our test groups, the greatest improvement in absorption efficiency is 85 %, and the largest improvement in COP is 13.7 %.
研究领域:
热力学
·
制冷工程
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2025
·
IF 3.3
Hao Yin,Bingxian Wu,Xueyang Leng,Hong Gao,Jing Yao
Electrolytic water-splitting has the advantages of high efficiency, environmental friendliness, and sustainability. It is becoming a leading approach for producing hydrogen. In order to improve the efficiency of water-splitting, a bifunctional electrocatalyst with high performance is needed. Herein, we present a novel approach to construct a bifunctional electrocatalyst for overall water-splitting by compounding Ni(OH)2 and CoP. This combination induced charge optimization, thereby leading to surface reconstruction. The nanocomposite displayed outstanding catalytic performance, benefiting from its more reactive surface area, improved conductivity and enhanced electrocatalytic activity. The resulting Ni(OH)2/CoP electrocatalyst exhibited excellent catalytic performance, with low overpotentials of 266 mV at 50 mA cm−2 for the OER and 71 mV at −10 mA cm−2 for the HER, and required only 1.54 V to reach 10 mA cm−2 in an overall water-splitting device, overtaking most of the recently reported Co- and Ni-based catalysts. This innovative strategy offers new directions for the design of efficient electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Yuanliang Yuan,Yisheng Yang,Hongxuan Xie,Xiaocong Zhong,Ruixiang Wang,Zhifeng Xu
Due to their distinctive electronic configuration, transition metal phosphides (TMPs) display remarkable catalytic ability in both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Several strategies have been proposed to increase the catalytic efficiency of TMPs, including heteroatom doping, morphology design, and interface engineering. In this study, CoP hollow nanoflower clusters doped with trace amounts of Fe (Fe–CoP nanoFC) were synthesized via a template-based hydrothermal reaction and high-temperature phosphatization. Compared with those of Fe 2 P and CoP, the OER and HER overpotentials (@10 mA cm −2 ) of the Fe–CoP nanoFC in alkaline solution (pH = 14) were 269 mV and 203 mV, respectively, outperforming those of commercial RuO 2 (326 mV) and 20% Pt/C (221 mV). The overall water electrolysis voltage with the Fe–CoP nanoFC as both HER and OER catalysts was 1.671 V (@10 mA cm −2 ), outperforming the 1.736 V achieved with commercialized Pt/C || RuO 2 . Furthermore, the voltage remained stable during the 14 h of galvanostatic water electrolysis, indicating the potential for long-term stability. Trace Fe doping facilitates the construction of abundant Fe 2 P/CoP heterojunctions, effectively modulates the charge distribution at the interface, and consequently enhances the OER/HER catalytic efficiency of CoP nanoFCs. DFT calculations indicate that the CoP/Fe 2 P heterojunction interface has a higher d-band center and greater local charge density. These properties increase the adsorption strength of OH∗, O∗ and OOH∗, reduce the free energy of adsorption of hydrogen atoms and improve the stability of H∗. As a result, the catalysts exhibit considerable catalytic capacity for the OER and HER.
研究领域:
材料科学
·
催化化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）