Photocatalytic H2 generation from aqueous ammonia solution using TiO2 nanowires-intercalated reduced graphene oxide composite membrane under low power UV light

Abstract

We report for the first time the nitrogen doping of reduced graphene oxide (rGO) and TiO2 nanowires (NWs) when TiO2 NWs intercalated rGO membranes were immersed in ammonia aqueous solution under 8 W 254 nm UV irradiation. Such nitrogen-doped rGO/TiO2 NWs photocatalytic membrane produced H2 at a rate of 208 μmol h−1 g−1 under 8 W 254 nm UV irradiation, which is more than 14 times higher than the yield of the TiO2-P25 and 30-fold higher than TiO2 NWs alone under the same condition. Our study demonstrates a new synthesis route for doping nitrogen in rGO and TiO2, as well as the preliminary feasibility of hydrogen extraction from ammonia-containing wastewater with such a low-cost recyclable photocatalyst. In addition, the study illustrates the complexity of photocatalysis of ammonia aqueous solution, which involves multiple reactions in concurrence.