| Electrocatalytic water splitting can obtain high purity H2 and O2 in a clean,environment-friendly and pollution-free process.But today’s highly capable precious metal catalysts are expensive and scarce.And the catalytic performance of cheap catalyst is not as good as precious metal catalyst.This makes the use of precious metal composite cheap catalysts to reduce cost and maintain performance an important choice.Transition metal nitrate hydroxides have recently been found to have excellent performance in oxygen evolution reaction（OER）among many cheap catalysts.The controlled growth of precious metals on the surface of transition metal nitrate hydroxide to form precious metal composites is expected to obtain materials with better hydrogen evolution reaction（HER）and OER activity to achieve excellent electrocatalytic performance of electrocatalytic water splitting.CoNO3（OH）?H2O on nickel foam（CoNH/NF）was prepared by molten salt method as precursor.Then,Pt-CoNH/NF was obtained by growing precious metal Pt nanoparticles on the precursor CoNH/NF by using simple UV bactericidal light irradiation of potassium chloroplatinate solution.At this time,the 0.5-Pt-CoNH/NF performance is the best in the OER.A current density of 10mA/cm2 can be reached at 289mV vs.Reversible hydrogen electrode（RHE）over-potential（η）.Among the HER,1-Pt-CoNH/NF has the best HER performance,whichη10 is 49mV vs.RHE.The 0.5-Pt-CoNH/NF shows the best total hydrolyzing performance.It only needs1.605V vs.RHE potential to achieve a current density of 10mA/cm2.At the same time,the stability of 0.5-Pt-CoNH/NF can also be maintained for more than 45h at10mA/cm2 constant current density.Ru nanoparticles are grown by sodium borohydride（NaBH4）reduction method to get Ru-CoNH/NF.The effect of Ru-CoNH/NF sample on HER performance is not high.Theη10 of 5-Ru-CoNH/NF material is almost not reduced compared to the precursor,η20 is reduced by 7mV compared to CoNH/NF,andη50 is only reduced by4mV.In OER,theη20of Ru-CoNH/NF can be as low as 305mV vs.RHE,showing excellent performance.2.5-Ru-CoNH/NF has excellent performance in total water decomposition.It only needs 1.659V vs.RHE to reach the current density of 10mA/cm2,but the long-term stability is not good enough. |
