Design And Studies Of Transition Metal Nanomaterials For Electrocatalytic Water Splitting

Energy shortage and environmental pollution are issues that cannot be ignored in the sustainable development of human society.The use of electrical energy to catalyze the decomposition of water to produce hydrogen and oxygen?2H₂O?2H₂+O₂?is the most promising way to obtain clean and renewable energy,and has attracted more and more attention from researchers.At present,noble metal-based catalysts such as commercial Pt/C,Ru O₂,Ir O₂ possessed the most excellent catalytic performance.However,their large-scale industrial applications are limited due to the scarcity and high cost.Therefore,the development of non-precious metal catalyst materials with abundance,low cost and high catalytic activity has become a research hotspot and focus in the field of hydrogen evolution reaction?HER?and oxygen evolution reaction?OER?.In this paper,carbon paper?CFP?was used as a template to synthesize Co?CO₃?_0.35Cl_0.20?OH?_1.10/CFP nanowire array precursor by hydrothermal method firstly,and then Mo O₂ was deposited by high temperature calcination via chemical vapor deposition.The bimetallic phosphide Mo P/Co₂P/CFP was obtained by high temperature phosphorization,and the HER performance as a cathode material was measured.The results showed that Mo P/Co₂P/CFP exhibited an overpotential of 140m V to drive 10 m A cm^-2,a Tafel slope of 80 m V dec^-1,a charge transfer resistance of12.53?and a double layer capacitance of 48.2 m F cm^-2 in 0.5 M H₂SO₄ solution.Moreover,after 1000 cycles of cyclic voltammetry in acidic electrolyte,the activity of the catalyst was almost no attenuation,indicating the excellent stability of Mo P/Co₂P/CFP.In addition,a commercial porous anodic aluminum oxide membrane?AAO?was used as a template to synthesize Ce-doped Ni?OH?₂ precursor by coprecipitation method,and followed by removing the AAO template with high concentration of Na OH solution.The precursor was then calcined in air to obtain the Ce-doped Ni O nanotubes and the OER performance as an anode material was investigated.The Ce-doped Ni₂P nanotubes was obtained by in situ phosphorization of the precursor and the HER performance as an cathode material was measured.The results showed that the Ce-doped Ni O nanotubes displayed good OER performance and stability in1.0 M KOH solution.To achieve a current density of 10 m A cm^-2,only an overpotential of 347 m V was required,with a Tafel slope of 115 m V dec^-1,a charge transfer resistance of 37.2?.Moreover,it still maintained good catalytic activity after1000 cycles.In addition,the Ce-doped Ni₂P nanotubes could reach 116 m V in 0.5 M H₂SO₄ solution at a current density of 10 m A cm^-2,with a Tafel slope of 59 m V dec^-1and a charge transfer resistance of 12.9?.And there was no significant attenuation of catalytic activity after the stability test.In summary,this work provided new strategies for the preparation of other highly efficient non-precious metal catalysts.