Construction and properties of highly efficient Ag6Si2O7/C-WO3 visible light photocatalyst for water purification

Abstract

Photocatalytic oxidation decomposes large molecules of organic pollutants that are difficult to biodegrade in a short period of time is a promising and effective strategy to alleviate water environmental crises. However, designing efficient, stable, and long-lasting photocatalysts remains a challenge. This article integrates C-WO₃ with Ag₆Si₂O₇ to form a Ag₆Si₂O₇/C-WO₃ heterojunction for the degradation of organic pollutants under visible light. This catalyst can capture a wider range of visible light and disperse photogenerated charges more efficiently, thus demonstrating extraordinary photocatalytic performance in photocatalytic oxidation and decomposition of large organic pollutants. After visible light irradiation for 40 min, the removal rate of organic matter reached 99.1 %, and the rate constant reached 0.0931 min⁻¹, which is 35.1 and 13.5 times that of WO₃ and C-WO₃ under the same conditions. Through free radical capture experiments, it was found that h⁺ plays a dominant role in photocatalytic reactions. In view of the analysis of valence band positions, a reasonable photocatalytic mechanism diagram including photo generated electron transfer pathways was drawn. This undertaking affords a new idea for constructing efficient photocatalysts for water purification.