Novel Ag2O-Ga2O3 type II p-n heterojunction as an efficient water cleanser for green cleaning technology

Abstract Ag2O-Ga2O3 based type II p-n nanoheterojunctions were fabricated using ex-situ chemical reduction technique with different densities of Ag2O attachment to gallia surface. A systematic optimization was carried out to establish the best performing junction aiming for the photodegradation of the noxious organic dye methyl orange (MO). Thorough theoretical and experimental studies were performed to determine relative band positions and ensure charge transfer between the counterparts. Favorable alignment of the electronic bands of Ag2O and Ga2O3 was identified as a key factor for the prompt separation of photogenerated e−/h+ pair leading to a faster decomposition of hazardous dyes. The optimized sample also performed remarkably fast in degrading carcinogenic phenol and other dyes like rhodamine B (RhB), aniline blue (AB), eosin B (EB) and mixtures of dyes with different ionic identities. Additional advantages of these catalysts were reflected in the retainment of catalytic efficiency over multiple water disinfection cycles and its performance in active media of different pH values was observed. With high degradation rate constants of 0.4158, 0.3306, 0.2436 and 0.207 min−1 for RhB, AB, MO, EB respectively and multidimensional performance as green cleaning agent, this newly explored Ag2O3-gallia nanoheterojunction is identified as a strong candidate for future water cleaning technology.