Novel and facile strategy for immobilization of Ag3PW12 crystals on graphitic carbon nitride (g-C3-N4) sheets, a superior photocatalyst for decomposition of organic waste

Abstract

The high electron-holes recombination rate in pure graphitic carbon nitride (C3–N4) restrict their photocatalytic efficiency. In this research work, we successfully immobilized Ag3PW12O40 a polyoxometalate-base crystal on graphitic carbon nitride 2D sheet through physical grinding method to prevent charges recombination on the surface. Both the materials were prepared separately and then grinded after mixing, to get C3–N4@Ag3PW12 heterojunction. The prepared C3–N4@Ag3PW12 composites were tested with different characterization techniques to confirm its structural integrity and successful fabrication of heterojunction. The composite catalyst showed expansion in UV light absorbance where it promotes from 406 nm to 454 nm for pure C3–N4 and composite C3–N4@Ag3PW12-30 % respectively. The composite showed better electron-holes separation, confirmed from its electrochemical performance such as TPC (total photocurrent) and PL data. The prepared catalysts were tested for the degradation of two types of organic dyes such as methylene blue and Rhodamine B under photoirradiation. The C3–N4@Ag3PW12-30 % composite photocatalyst showed efficient photocatalytic activity and removed 99 % methylene blue in 75 min while removed 99.4 % Rhodamine B in 60 min while the pure Ag3PW12 and C3–N4 could only remove 26.3 % and 37.7 % methylen blue and 43.54 % and 53.38 % rhodamin B respectively, in the same conditions. The results show that, the Ag3PW12 crystals deposition on C3–N4 2D sheets is a preferred approach to enhance the catalytic performance of C3–N4 2D sheet.