1.School of Chemistry and Chemical Engineering,Yan’an University
2.Research Institute of Comprehensive Energy Industry Technology
3.Engineering Research Center of Oil and Gas Resource Efficient Development and Ecological Environment Protection of Shaanxi Universities,Yan’an 716000,China
Replacing the oxygen evolution reaction (OER) in the anode with a small molecule oxidation reaction and coupling it with the hydrogen evolution reaction (HER) in the cathode can significantly enhance hydrogen production efficiency and reduce energy consumption. Based on this, in this paper, a high-performance non-noble metal sulfide bifunctional electrocatalyst (NiS/Co9S8) with a nano-sheet structure was prepared by a one-step hydrothermal method, and the phase structure, hydrogen evolution reaction, oxygen evolution reaction and urea oxidation performance of the catalyst were studied. The results show that the NiS/Co9S8 catalyst is uniformly distributed on the nickel foam (NF) as nano-protrusions, with a rough surface and many exposed active sites, and has a good microstructure. During the reaction, Co3+ is formed in the composite catalyst, and the presence of Co3+ results in a HER voltage of only 89 mV at an initial current density of 10 mA·cm-2, with a Tafel slope of approximately 129 mV·dec-1. Under the same conditions, the OER of NiS/Co9S8 has a lower overpotential. When 0.5 mol·L-1 urea is added to the electrolyte solution, the NiS/Co9S8 catalyst has a smaller overpotential and Tafel slope, and after 50 h of stability testing, it shows good urea oxidation performance and long-term stability. This study can provide guidance for the hydrogen production coupled with urea oxidation using non-noble metal electrocatalysts.
WUT H, QIUZ T, HSIEHC N,et al. An organic-inorganic heterojunction electrocatalyst for highly efficient urea oxidation[J]. Journal of Materials Chemistry A,2024,12(37):25186-25192.
[2]
CAIM M, ZHUQ, WANGX Y,et al. Formation and stabilization of NiOOH by introducing α-FeOOH in LDH:Composite electrocatalyst for oxygen evolution and urea oxidation reactions[J]. Advanced Materials,2023,35(7):e2209338.
JIANGH, XIAJ, JIAOL,et al. Ni single atoms anchored on N-doped carbon nanosheets as bifunctional electrocatalysts for Urea-assisted rechargeable Zn-air batteries[J]. Applied Catalysis B:Environmental,2022,310:121352.
YINZ H, HUANGY, JIANGL W,et al. Revealing the in situ evolution of tetrahedral NiMoO4 micropillar array for energy-efficient alkaline hydrogen production assisted by urea electrolysis[J]. Small Structures,2023,4(9):2300028.
[7]
FENGD M, YER Z, TONGY,et al. Engineering cobalt molybdate nanosheet arrays with phosphorus-modified nickel as heterogeneous electrodes for highly-active energy-saving water splitting[J]. Journal of Colloid and Interface Science,2023,636:425-434.
[8]
DINGX Y, LIUD, ZHAOP J,et al. Dynamic restructuring of nickel sulfides for electrocatalytic hydrogen evolution reaction[J]. Nature Communications,2024,15(1):5336.
[9]
CAOD F, LIUD B, CHENS M,et al. operando X-ray spectroscopy visualizing the chameleon-like structural reconstruction on an oxygen evolution electrocatalyst[J]. Energy & Environmental Science,2021,14(2):906-915.
[10]
WANGY S, ZHAOY G, LUY,et al. Surficial reconstruction of Pt-Ni/NiS and its effect on electrocatalytic hydrogen evolution in alkaline medium[J]. ACS Applied Materials & Interfaces,2024,16(34):44879-44888.
VENKATESAND, ANNAMALAIT, RAMKUMARS,et al. Carbon-supported Co9S8 hollow spheres assembled from ultrathin nanosheets for high-performance supercapacitors[J]. Journal of Materials Science:Materials in Electronics,2024,35(16):1051.
[13]
XIAOY H, SHENY, SUD C,et al. Engineering Cu1.96S/Co9S8 with sulfur vacancy and heterostructure as an efficient bifunctional electrocatalyst for water splitting[J]. Journal of Materials Science & Technology,2023,154:1-8.
[14]
WUL, LIS X, LIL X,et al. Modest modulation on the electronic structure of Co9S8 by vanadium doping for high-performance rechargeable Zn-air batteries[J]. Applied Catalysis B:Environmental,2023,324:122250.
[15]
WANGN, WANGL Y, YANGS H,et al. Interface engineering of Co9S8-Ni3S2/Cu heterogeneous electrocatalyst for enhanced HMF oxidation[J]. Applied Surface Science,2025,689:162401.
[16]
GAOC, KONGL H, PANL,et al. A novel sacrificial solvent method to synthesize self-supporting Co9S8/Ni3S2 heterostructure catalyst for efficient oxygen evolution reaction[J]. Journal of Colloid and Interface Science,2023,652:1756-1763.
[17]
PANGQ Q, SUNK H, FANX Z,et al. Enhancement effect from ReS2/Co9S8 heterostructure evolution for the highly effective furfural oxidation coupling with hydrogen production[J]. Chemical Engineering Journal,2024,497:154475.
[18]
GUOP, CAOS F, HUANGW J,et al. Heterojunction-induced rapid transformation of Ni3+/Ni2+ sites which mediates urea oxidation for energy-efficient hydrogen production[J]. Advanced Materials,2024,36(18):e2311766.
[19]
YANGS W, GUOY, ZHAOY K,et al. Construction of synergistic Ni3 S2-MoS2 nanoheterojunctions on Ni foam as bifunctional electrocatalyst for hydrogen evolution integrated with biomass valorization[J]. Small,2022,18(24):e2201306.
[20]
ZHOUA, CAIW W, FANY C,et al. Crystal phase engineering of CoBOx/NiCoP heterostructures as trifunctional electrocatalysts for overall water splitting and urea electrolysis[J]. Chemical Engineering Journal,2024,494:152973.
[21]
TAMILARASIS, KUMARR S, KIMA R,et al. Boosting the production of hydrogen from an overall urea splitting reaction using a tri-functional scandium-cobalt electrocatalyst[J]. Small,2024,20(49):e2405939.
[22]
LUOF, PANS Y, XIEY H,et al. Atomically dispersed Ni electrocatalyst for superior urea-assisted water splitting[J]. Journal of Energy Chemistry,2024,90:1-6.
[23]
YIP, SONGY Y, LIUZ K,et al. Boosting alkaline urea oxidation with a nickel sulfide/cobalt oxide heterojunction catalyst via interface engineering[J]. Advanced Composites and Hybrid Materials,2023,6(6):228.
[24]
MAM J, XUJ H, WANGH Q,et al. Multi-interfacial engineering of hierarchical CoNi2S4/WS2/Co9S8 hybrid frameworks for robust all-pH electrocatalytic hydrogen evolution[J]. Applied Catalysis B:Environmental,2021,297:120455.