Ag3PO4/In(OH)3 Composite Photocatalysts with Adjustable Surface-Electric Property for Efficient Photodegradation of Organic Dyes under Simulated Solar-Light Irradiation

A new composite photocatalyst Ag3PO4/In(OH)3 was successfully synthesized via in-situ precipitation method and applied to eliminate Rhodamine B under the irradiation of solar simulator. The composite photocatalysts exhibited higher activities than that of individual Ag3PO4 and In(OH)3, and the highest activity (the rate constant kapp = 1.75 min–1) was observed over the Ag3PO4/In(OH)3 with a molar ratio of 1.65:1.00. The further mechanism study and material characterizations indicated that the photocatalytic activity is closely related to the surface-electric property of the composite photocatalyst. Moreover, the surface-electric property could be continually adjusted by changing the content of In(OH)3.The photosensitization and the intrinsic photocatalytic degradation of Rh B were investigated under 540 ± 12 and 420 ± 12 nm monochromatic irradiation, respectively. The results indicated that the intrinsic photocatalytic degradation of Rh B dominated the overall degradation under the solar light irradiation. The energy-band structure of the composite photocatalyst was also investigated and considered as a reason for the enhanced multielectron reactions. Here, the composite photocatalysts with adjustable surface-electric property and suitable energy-band structure reveal a material design concept of exploiting a new photocatalyst based on the reaction kinetics and thermodynamics.