Prism-like integrated BiWO with Ag-CuBiO on carbon nanotubes (CNTs) as an efficient and robust S-scheme interfacial charge transfer photocatalyst for the removal of organic pollutants from wastewater.

Photocatalytic hybrid carbon nanotubes (CNTs)-mediated Ag-CuBiO/BiWO photocatalyst was fabricated using a hydrothermal technique to effectively eliminate organic pollutants from wastewater. The as-prepared samples were characterized via Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction patterns (XRD), high-resolution transmission electron microscope (HR-TEM), UV-vis Diffuse Reflectance spectrum (UV-Vis DRS), and photoluminescence (PL) studies. The photocatalytic performance of fabricated pristine and hybrid composites was examined by photo-degradation of toxic dye viz. Rhodamine B (RhB) under visible light. Photo-degradation results revealed that the fabricated Ag-CuBiO/CNTs/BiWO semiconductor photocatalyst followed pseudo-first-order kinetics and displayed a higher photocatalytic rate, which was found to be approximately 3.33 and 2.35 times higher than the pristine CuBiO and BiWO semiconductor photocatalyst, respectively. Re-cyclic results demonstrated that the formed composite owns excellent stability, even after five consecutive cycles. As per the matched Fermi level of CNTs in between Ag-CuBiO and BiWO, carbon nanotubes severed as electron transfer-bridge, Ag doping on CuBiO surface successfully increased photon absorption all across CuBiO surface. Also, it hindered the assimilation of photoinduced electron-hole pairs. The increased photocatalytic efficiency is contributed to the uniform dispersion of photo-generated electron-hole pairs via the construction of an S-scheme system. ROS trapping and ESR experiments suggested that (∙OH) and (O∙) were the main radical species for enhanced photo-degradation of RhB dye. The current investigation, from our perspective, highlights the new insights for the fabrication of practical CNTs-mediated S-scheme-based semiconductor photocatalyst for the resolution of environmental issues based on practical considerations.