Rational sonochemical engineering of Ag2CrO4/g-C3N4 heterojunction for eradicating RhB dye under full broad spectrum
Ali Alsalme, Mohamed M. Hassan, Mohamed A. Eltawil, A.E. Amin, Ayman Soltan, M. F. Abdel-Messih, M.A. Ahmed
Abstract
In this novel research, S-scheme Ag 2 CrO 4 /g-C 3 N 4 heterojunctions were generated by sonochemical hybridization of different compositions of Ag 2 CrO 4 nanoparticles [E VB =+2.21 eV] and g-C 3 N 4 sheets [E CB =-1.3 eV] for destructing RhB dye under artificial solar radiation. The as-synthesized nanocomposites were subjected to X-ray diffraction [XRD], diffuse reflectance spectrum [DRS], X-ray photoelectron spectroscopy [XPS], N 2 -adsorption-desorption isotherm, photoluminescence [PL] and high resolution transmission electron microscope [HRTEM] analysis to explore the interfacial interactions between g-C 3 N 4 sheets and Ag 2 CrO 4 nanoparticles. Spherical Ag 2 CrO 4 nanoparticles deposited homogeneously on the wrinkles points of g-C 3 N 4 sheets at nearly equidistant from each other facilitating the uniform absorption of solar radiations. The absorbability of solar radiations was enhanced by introducing 20 wt % Ag 2 CrO 4 on g-C 3 N 4 sheets. The surface area of g-C 3 N 4 sheets was reduced from 37.5 to 16.4 m 2 /g and PL signal intensity diminished by 80 % implying the successful interfacial interaction between Ag 2 CrO 4 nanoparticles and g-C 3 N 4 sheets. The photocatalytic performance of heterojunctions containing 20% Ag 2 CrO 4 and 80 % g-C 3 N 4 destructed 96 % of RhB dye compared with 60 and 33 % removal on the surface of pristine g-C 3 N 4 sheets and Ag 2 CrO 4 , respectively. Benzoquinone and ammonium oxalate are strongly scavenged the dye decomposition revealing the strong influence of valence band holes of Ag 2 CrO 4 and superoxide radicals in destructing RhB dye under solar radiations. S-scheme charge transportation mechanism was suggested rather than type II heterojunction on the light of scavenger trapping experiments results and PL spectrum of terephthalic acid. Overall, this research work illustrated the manipulation of novel S-scheme heterojunction with efficient redox power for destructing various organic pollutants persisted in water resources.