Transition metal dichalcogenides (TMDs) are promising materials for photocatalytic functions. In class of TMDs, MoS₂ is comprehensively explored as a co-catalyst due to the extraordinary activity for photocatalytic activity of organic dye degradation. But the catalytic activities of MoS₂ are generated through S ions on depiction edges. Also numerous of S ions existed on basal planes are catalytically inactive. The insertion of external metals in MoS₂ organism is extensive way for activation of basal planes surface to enhance concentration of catalytically active sites. For this purpose, nanoparticles of Nickel (Ni) doped MoS₂ are prepared by hydrothermal technique. Structural and morphological analysis are characterized by XRD and SEM, respectively. XRD results showed that Ni is completely doped into MoS₂. SEM showed that pure MoS₂ has sheet like structure and Ni doped MoS₂ has mix disc and flower like structure. Band gap energy was observed in declining range of 2.30–1.76 eV. The photocatalytic activity of pure MoS₂ and Ni doped MoS₂ were evaluated by degrading MB and RhB dyes under UV light irradiation. MB dye degradation of MB was 71% for pure MoS₂. For 1% to 5% Ni doping in MoS₂, MB dye degradated from 85% to 96%. It means that MB dye degradation of MB was enhanced continuously by increasing the concentration of Ni doping. RhB dye degradation of RhB was 62% for pure MoS₂. For 1% to 5% Ni doping in MoS₂, the RhB dye degradated from 77% to 91%.

In view of enhanced bioactivity and photocatalytic applications, the doped material has gained much attention and present study was focused on the preparation of Zn doped WO₃ (Zn–d–WO₃) via precipitation method. The prepared Zn–d–WO₃ was characterized by Scanning Electron Microscopy (SEM), x-ray diffraction (XRD), Energy-dispersive x-ray (EDX). The effect of Zn concentration was studied on antibacterial, antifungal and photocatalytic activities along with structural and morphological variation. The Zn–d–WO₃ was triclinic, spherical and rod shaped and particle size was decreased as the Zn concentration increased. The antimicrobial activity of Zn–d–WO₃ was evaluated against a panel of bacterial strains (Escherichia coli, Pasturellamu ltocida, Bacillus subtilis, Staphylococcus aureus) and fungal strain (Aspergillus niger, Aspergillus flavus, Penicillium notatum). The Zn–d–WO₃ showed promising antibacterial activity with minimum inhibitory concentration (MIC) values in the range of 211–387 (μg ml⁻¹), whereas the antifungal activity was less than the standard (Fluconazole), which revealed that the Zn–d–WO₃ are highly active against bacterial strains since activity was comparable with standard drug (Rifampicin). The photocatalytic activity (PCA) was evaluated by degrading methylene blue (MB) dye in an aqueous solution and dye degradation of 78% and 92% was achieved in 120 min under visible and UV irradiation, respectively. Results revealed that the Zn–d–WO₃ could possibly be used as photocatalyst for the degradation of dyes in wastewater.

Currently, the green route for synthesis of silver nanoparticles (Ag NPs) using plants leaf extract is an emerging research area in nanotechnology. The present study was explored for synthesis, characterization and catalytic application of Ag NPs using Diospyros lotus fresh leaf extracts. Factors affecting the synthesis were optimized and optimum conditions were pH of 8.6, silver nitrate (AgNO ₃ ) concentration of 1.5 mM and 10 mL leaf extract. Formation of Ag NPs was observed by change in color of reaction mixture from pale yellow to reddish brown. The synthesized Ag NPs were characterized using UV-Vis spectrophotometer, EDX, XRD and SEM analyses. UV-Vis spectrophotometer showed maximum absorbance peak in the range of 407 nm at different time intervals indicating formation of Ag NPs. SEM and XRD analysis confirmed face centered cubic structure and crystalline nature of biologically synthesized Ag NPs with average particle size of 27 nm. The purity of synthesized Ag NPs was revealed by EDX. Finally, photo catalytic activity (PCA) of Ag NPs was studied and 72.91% decolorization of industrial waste water was obtained at 54 h. Some important parameters like pH, turbidity, conductance; TSS, TDS, sulphide, sulphates, etc. were also monitored before and after treatment with Ag NPs.