Novel Fe2(MoO4)3/g-C3N4 heterojunction for efficient contaminant removal and hydrogen production under visible light irradiation

Abstract

Novel Fe2(MoO4)3/g-C3N4 composites were synthesized by a facile mixing-calcination method. The photocatalytic activity of the Fe2(MoO4)3/g-C3N4 hybrid was evaluated via RhB degradation and H2-production under visible light irradiation. Results indicated that the Fe2(MoO4)3/g-C3N4 binary composite exhibited excellent photocatalytic activity. The optimal hybrid could produce hydrogen 6.6 times faster than pure g-C3N4 from water-methanol solution under visible light irradiation. For the photocatalytic degradation of RhB, it showed a degradation rate of 0.070min−1, which was 7.8 times higher than that of pure g-C3N4. Moreover, the composite showed high stability and extensive adaptability in degradation of other organic pollutants. The N2 physical absorption measurement and UV–visible diffuse reflection spectroscopy suggested that the coupling of Fe2(MoO4)3 increased the BET specific surface area and visible light absorption, both of which favored the photocatalytic reaction. However, the main reason of the enhanced activities were attributed to the interfacial transfer of photogenerated electrons and holes between Fe2(MoO4)3 and g-C3N4, leading to the effective charge separation in the composite, which were evidenced by photoluminescence spectroscopy and photocurrent analysis. This work may provide some useful information for the future design and practical application of multifunctional hybrids photocatalysts in water purification.