Impact of alternate Mn doping in ternary nanocomposites on their structural, optical and antimicrobial properties: Comparative analysis of photocatalytic degradation and antibacterial activity.

The present study was done to investigate and compare the photocatalytic and antibacterial activity of two in situ Manganese doped ternary nanocomposites. The dual ternary hybrid systems comprised Mn-doped Ag2WO4 coupled with MoS2-GO and Mn-doped MoS2 coupled with Ag2WO4-GO. Both hierarchical alternate Mn-doped ternary heterojunctions formed efficient plasmonic catalysts for wastewater treatment. The novel nanocomposites were well-characterized using XRD, FTIR, SEM-EDS, HR-TEM, XPS, UV-VIS DRS, and PL techniques confirming the successful insertion of Mn+2 ions in respective host substrates. The bandgap of the ternary nanocomposites evaluated by the tauc plot showed them visible light-active nanocomposites. The photocatalytic ability of both Mn-doped coupled nanocomposites was investigated against the dye methylene blue. Both ternary nanocomposites showed excellent sunlight harvesting ability for dye degradation in 60 min. The maximum catalytic efficiency of both photocatalysts was obtained at a solution pH value of 8, photocatalyst dose and oxidant dose of 30 mg/100 mL and 1 mM for Mn-Ag2WO4/MoS2-GO, 50 mg/100 mL, 3 mM for Mn-MoS2/Ag2WO4-GO keeping IDC of 10 ppm for all photocatalysts. The nanocomposites showed excellent photocatalytic stability after five successive cycles. The response surface methodology was used as a statistical tool for the evaluation of the photocatalytic response of several interacting parameters for dye degradation by ternary composites. The antibacterial activity was determined by the inactivation of gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria by support-based doped ternary hybrids.

g-C3N4/graphene oxide/SnFe2O4 ternary composite for the effective sunlight-driven photocatalytic degradation of methylene blue.

A broadly used dye, methylene blue (MB), adversely impacts human health and water resources, which triggers efficient methods for its elimination. Semiconductor-based heterogeneous photocatalysis is an environmentally friendly approach that effectively degrades organic pollutants. The purpose of the current work is to elucidate and validate the application of a promising g-C3N4/GO/SnFe2O4 (CGS) composite for the environmental remediation of methylene blue dye. The ternary CGS composite has been synthesized using a solvothermal approach. The fabricated composites were analyzed through FTIR, XRD, SEM/EDX, UV-VIS spectroscopy, TEM, and XPS. The photoactivity of composites and affecting parameters (pH, H2O2 dosage, composite amount, initial dye concentration, and irradiation time) were observed in sunlight illumination. The optimal conditions for photocatalytic degradation were pH = 5, photocatalyst dosage = 30 mg/100 mL, H2O2 dosage = 6 mM, and initial dye concentration (IDC) of 10 ppm employing ternary CGS composite, and MB dye was degraded effectively within 1 h. Ninety-eight percent degradation efficacy was attained by employing ternary CGS composite under the optimized conditions. Scavenging analysis suggested that •OH radicals were the key reactive oxygen species (ROS) responsible for the photodegradation of MB dye. Furthermore, the CGS nanocomposite exhibited outstanding recyclability of 84% after five consecutive runs, demonstrating its potential for use in practical applications, particularly pollutant removal.