Studies On The Synthesis And Modification Of Low Cost Clectrocatalysts For Water Splitting

The demand of energy is growing with the rapid development of the global economy.Fossil fuels,as the traditional energy source,are deficient in reserves,harmful to the environment,and will produce a large amount of greenhouse gases.Therefore,developing the new energy technology to solve the energy problems is the key point.Hydrogen energy stands out among the various energy technologies due to its abundant sources,environment friendliness and safety.Electrolysis of water for hydrogen production is theoretically the best choice,because the other methods are still dependent on fossil fuels.At present,the main challenge of electrolysis of water to hydrogen is the high cost of catalyst.The main ways to reduce the cost are to use non-noble metal catalyst and reduce the mass load of noble metal into the noble metal catalyst.We try to do these two approaches in this paper respectively.(1)CU7S4 nanosheet was prepared by the solvent hot method as the precursor.Doping the Co element into the nanosheet would produce some new active sites for oxygen evolution reaction over the surface of catalysts.When the current density reaches 10 mA cm-2 in alkaline solution,the overpotential is only 270 mV.In addition,the tafel slope and turnover frequency of the catalyst are much better than the original Cu7S4 nanosheet.(2)Nickel was doped into the noble metal platinum to reduce the platinum load on the catalyst.The results,in the alkaline solution,showed that the catalyst not only maintained high HER catalytic activity,but also showed OER catalytic activity that platinum did not have.In the test of overall water splitting of alkaline solution,the overpotential of PtC-RuO2 was 417.3 mV,and the improved catalyst of PtNi3O showed the overpotential of 362.2 mV.The catalyst of PtNi3O was also superior to PtC-RuO2 in terms of electrochemical activity surface area and tafel slope.