Microwave-assisted Preparation of Copper Hydroxyphosphate and Characterization of Photocatalysis under Visible Light

Copper hydroxyphosphate (Cu2(OH)PO4) was quickly synthesized by microwave-assisted method at low temperature (< 100°C) and normal atmosphere pressure, then characterized by XRD, SEM and Raman spectra. The synthesis parameters were investigated by a series of controled experiments. It is found that molar ratio, initial concentration of CuCl2 and NaH2PO4, and surfactant species were crucial factors determining the formation and morphology of Cu2(OH)PO4. Cu2(OH)PO4 synthesized at different [PO4] (n(Cu)/n(P)=2) exhibited a various morphologies including grain-like, prism and long-prismatic. Addition of anionic surfactant and sodium dodecyl sulfate (SDS) greatly affects Cu2(OH)PO4 final morphology. The photocatalytic degradation of Cu2(OH)PO4 on methylene blue (MB) was evaluated with addition of H2O2 under visible light irradiation. The results showed that Cu2(OH)PO4 synthesized at conditions when n(Cu)/n(P)=2, [PO4]=0.0025 mol/L, 6.0 g urea and 0.10 g SDS, microwave heating at 80°C for 30 min exhibited best visible-light photo-degradation activity. The increase in HO· formation in the presence of Cu2(OH)PO4 and the inhibition of HO· generation by adding HO· scavengers (t-butanol) indicated that HO· generated 422 无 机 材 料 学 报 第 31 卷 in the reaction system was responsible for the enhanced MB decomposition. Cu2(OH)PO4 exhibited excellent stability and effectiveness after 5 consecutive runs in terms of photodegradation of MB.