Nitrogen-rich g-C3N4@AgPd Mott-Schottky heterojunction boosts photocatalytic hydrogen production from water and tandem reduction of NO3− and NO2−

Abstract

Developing an effective photocatalytic denitrification technology for NO3− and NO2− in water is urgently needed. In this paper, we synthesized a nitrogen-rich g-C3N4, and in-situ grown AgPd nanowires (NWs) on the surface of nitrogen-rich g-C3N4 to build AgyPd10−y/g-CxN4 Mott-Schottky heterojunction. Compared with g-CxN4, AgyPd10−y/g-CxN4 exhibits the enhanced photocatalytic hydrogen production from water and tandem reduction of NO3− and NO2− without the addition of other hydrogen source under 365 nm irradiation. The catalytic activity and selectivity of AgyPd10−y/g-CxN4 were studied by combination of the nitrogen-rich g-C3N4 and the different component of AgyPd10−y nanowires (NWs). Among the AgyPd10−y/g-CxN4 catalyst, the Ag3Pd7/g-C1.95N4 catalyst exhibited the highest photocatalytic activity and selectivity for photocatalytic reduction of NO3− and NO2−, and the removal rate of NO3− and NO2− are 87.4% and 61.8% under 365 nm irradiation at 25 °C, respectively. The strategy opens a new way for making the photocatalytic hydrogen production in tandem with reduction of NO3− and NO2− in water, also extending it to remove metal ion.