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This work presents a modified solvothermal process for a facile synthesis of high thermally stable nanocrystalline anatase TiO2 NPs doped with Cu2O NPs. A Z-scheme mechanism was used to account for the enhanced photocatalytic activity exhibited by these materials. Also, the nanocomposite was impregnated in cotton fabric to obtain a modified fiber with high thermal stability, self-cleaning, enhanced UV protection, and antibacterial activity. The as-prepared nanomaterials and the coated fabric were characterized by various physicochemical techniques such as XRD, EDXRF, TGA, TEM, HRTEM, and SEM. The Cu2O/TiO2 molar ratio in the nanocomposite was found to possess a pronounced impact on the crystalline structure, size and morphology of TiO2 NPs. The XRD revealed proper substitutions of the few Ti4+ sites by Cu2+ ions in TiO2 host lattice. Optical measurements showed that the plasmonic peak of the Cu2O/TiO2 nanocomposite was affected by the copper-doping concentration, enhancing self-cleaning of Cu2O/TiO2 under direct sunlight. The TiO2/fiber self-cleaning efficiency (12 h for MB removal) was increased by the in situ growing of Cu2O (5.5 h). Antibacterial activity studies revealed high potential activity of Cu2O/TiO2 against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Kleissella pneumonia, Saccharomyces sp.) bacteria. The promising photocatalytic and biocidal activity of our synthesized Cu2O/TiO2 nanocomposites was ascribed to the reactive oxygen species generated by the Z-scheme mechanism under direct Sunlight.

Multifunctional nanocatalyst that is efficient in removal of organic and inorganic contaminant under different light illumination is highly anticipated. Here, we report a ternary nanocatalyst that has catalytic, photocatalytic and a good photocatalytic memory for oxidation/reduction processes. The ternary nanocatalyst was prepared by the facile immobilization of Ag NPs on the V2O5/g-C3N4 surface by photodeposition method. The morphology of the ternary nanostructure shows the uniform distribution of V2O5 on the g-C3N4 surface decorated with 20–30 nm average diameters of Ag NPs. The prepared catalyst exhibits unique catalytic, photocatalytic and post-oxidation/reduction ability for removal of organic, p-nitrophenol (NP), methylene blue (MB) and inorganic (Cr+6) water pollutants. The catalytic reduction conversion of NP was completed in 60 min was ascribed to the electron relay mechanism, while the photocatalytic hydrogenation of NP was achieved in only 8 min and assigned to the solid Z-scheme electron-hole pair generation facilitated by the good electron storage of Ag NPs. On the other hand, the electron storage memory of the photocatalyst was responsible for the post- oxidation/reduction of MB/Cr+6 respectively. Oxidation of MB increased by 27%, while the Reduction of Cr+6 to Cr+3 was enhanced by 28% after sunlight post-illumination. The proposed ternary nanocatalyst provide an efficient tool for the removal of water pollutants from different sources during the daytime: in presence of sunlight or after the sunset.

Synergism between adsorption and photocatalytic activity in heterocatalysis improve the overall performance of organic and inorganic pollutants removal. We report the WO3/GO composite immobilized on chitosan to enhance the adsorption process and decorated with Ag NPs for efficient photocatalytic visible light absorption. The ternary photocatalyst (x%Ag/WO3/GO (x = 0, 1, and 3) was characterized by SEM, TEM, XRD, FTIR, XPS, and UV–Vis techniques. The obtained results show that both GO sheets and CS enhanced the adsorption process, while Ag NPs enhance the photocatalytic performance of WO3/GO composite. As expected, the 3 %Ag/WO3/GO shows excellent catalytic and photocatalytic performance of the removal of organic (methylene blue, and p-nitrophenol) and inorganic (Cr6+) water pollutants. 3 %Ag/WO3/GO composite removes 98% of MB (20 min) in absence of light, where more than 98% of MB (8 min) and 95% of p-nitrophenol (8 min) were removed after visible light irradiation. Enhanced adsorption of MB and Cr6+ was attributed to π-π stacking and electrostatic attractive potential over the catalyst, respectively. Based on the experimental results and trapping experiments, the charge separation through the Z-scheme WO3/GO facilitate the charge migration and boost the photocatalyst performance.