Facile synthesis of MgS/Ag2MoO4 nanohybrid heterojunction: Outstanding visible light harvesting for boosted photocatalytic degradation of MB and its anti-microbial applications

Abstract In this paper, a novel MgS/Ag2MoO4 nanocomposite (NCs) was synthesized for the evaluation of photocatalytic performance and anti-microbial activity. The particle was characterized using FT-IR, PL, HR-TEM, EDAX, XRD, XPS, SAED, UV–vis DRS, ESR, and EIS. The performance of the photocatalyst was improved by shift in band gap to 2.76 eV compared to its individual counter parts. The photocatalytic performance of MgS/Ag2MoO4 NCs was much better than MgS and Ag2MoO4 as individual particles. The reaction rate constant for degrading MB by MgS/Ag2MoO4 was 0.011 min−1. The degradation efficiency of MgS/Ag2MoO4 (90%) was about 1.5 and 2.2 times greater than bare Ag2MoO4 (62%) and MgS (41%). The photocatalytic degradation efficiency remains same with 90% efficiency after performing the reusability test for six consecutive cycles under visible light irradiation and the particles maintained photo stability even after 6 cycles. The strong interactions between the interfacial surfaces are responsible for the increase in charge separation owing to the superior activity of MgS/Ag2MoO4 NCs. The mechanism was established for this enhanced activity and the key reactive species, such as hydroxyl and superoxide radicals plays a major role in the photocatalytic process. The antimicrobial activity was evaluated against E. coli and B. subtilis and the activity of Ag2MoO4 was good compared to NCs and MgS. The synthesized NCs are found to be good alternative as a visible light driven photocatalyst.