Hydrogen Evolution Process Of Water Electrolysis Assisted By TiO₂ Nanotubes And TiO₂/ZnO Nanorodes Assembled On Ni Substrate

TiO2 nanotube arrays (TiO2NTs) and TiO2/ZnO nanorode arrays (TiO2/ZnO NRs) were successfully assembled on the Ni substrate by sol-gel method and layer by layer method respectively. And the composite anode sensitive to ultraviolet light was obtained. Based on the traditional alkaline electrolytic cell of water electrolysis, using Ni-Cr alloy as cathode, perfluorinated ion exchange membrane (GEFC) as diaphragm,30% NaOH as electrolyte, the device of water electrolysis assisted by photocatalysis (WEAP) was built by the irradiation of ultraviolet light on the anodes. Photocatalytic hydrogen evolution process was coupled with water electrolysis process. And a new process of hydrogen evolution, called as the hydrogen evolution of water electrolysis assisted by photocatalysis (WEAP), was proposed and experimentally achieved. And the efficiency of hydrogen evolution in WEAP process was improved remarkably compared with traditional alkaline electrolytic cell of water electrolysis. Meanwhile the voltage of water electrolysis was decreased, thereby reduced the consumption of electric power. The effect of photocatalytic materials, modification methods of the anode and process conditions of WEAP on the efficiency of hydrogen evolution was investigated. The experimental results show that when using ZnONRs as a hard template, whether use sol-gel method or layer by layer method, the WEAP hydrogen evolution efficiency of TiO2/ZnONRs assembled on Ni substrate was higher than the TiO2NTs. And the hydrogen evolution rate of TiO2/ZnONRs and TiO2NTs assembled on the Ni substrate were significantly improved comparing to the traditional alkaline electrolytic cell of water electrolysis. Comparison to traditional alkaline electrolytic cell of water electrolysis with sole Ni anode, the WEAP hydrogen evolution efficiency of TiO2/ZnONRs and TiO2NTs assembled on the Ni substrate by sol-gel method was increased by 153% and 122% respectively. And the consumption of electric power was decreased by 10.0% and 8.5% respectively. The WEAP hydrogen evolution efficiency of TiO2/ZnONRs and TiO2NTs assembled on the Ni substrate by layer by layer method was improved by 175% and 151% respectively. And the consumption of electric power was decreased by 10.5% and 9.0% respectively.