Photocatalytic performances of heterojunction catalysts of silver phosphate modified by PANI and Cr-doped SrTiO for organic pollutant removal from high salinity wastewater.

In this work, AgPO/PANI/Cr:SrTiO photocatalysts were designed to effectively eliminate organic pollutants including Rhodamine B and phenol from high salinity wastewater under visible light. The phase composition, optical properties, and morphology of powders were studied, and the effects of inorganic salts on removal performance of the as-prepared particles were also tested. Results showed that the photocatalytic activities of AgPO/PANI/Cr:SrTiO composites for Rhodamine B and phenol reached 100% within 10 min and 18 min, respectively. The reaction rate of pure AgPO was 7 times less than that of the ternary composite with the adding of PANI and Cr:SrTiO. The activity of AgPO/PANI/Cr:SrTiO remained at 92.25% after five cycles, so the photocatalytic and recyclable performance of ternary composite was greatly improved. In addition, when there was SO with a content of ranging from 1% to 21%, the degradation activity of the ternary catalyst under visible light was not changed for Rhodamine B, which indicated that the ternary catalyst exhibited the excellent sulfate resistance ability. Results from ESR and radical trapping experiments showed that O and h made an important contribution to visible-light photocatalytic activities.