One-pot citric acid/nitrates combustion design of 2D nanosheet mesoporous BiαClβOδ nanostructure: Efficient sunlight photocatalytic elimination of tetracycline-HCl

Abstract

The development of high-efficiency and stable nano-photocatalysts for environmental pollution control is a rapidly evolving research domain. The fabrication of Z-scheme heterojunctions with exceptional redox abilities has emerged as a promising and effective approach. In this study, the Z-scheme heterojunction sheet-like photocatalyst was created using a one-pot citric acid/nitrates combustion method, consisting of BiαClβOδ. To optimize the photocatalyst's physicochemical properties, the synthesis process was conducted at different fuel to oxidizer ratios (Φ = 0.25, 0.5, 0.75, 1), which is a critical factor in the combustion reaction. Compared to the pristine BiOCl with a photocatalytic efficiency of 65%, heterojunction nanosheets with a Φ ratio of 0.5 exhibited superior performance in completely removing aqueous tetracycline-HCl under simulated solar light irradiation. This boosting performance is mainly due to the improved light harvesting (Eg = 2.52 eV), charge separation and transfer resulting from the Z-scheme structure, as well as the increased pore volume (0.565 cm3/g) and specific surface area (127.9 m2/g) and well-grown sheet-like morphology resulting from the high temperature, heat, and released gases during combustion. These characteristics were confirmed using various analytical techniques, including DRS, XRD, BET-BJH, FESEM, EDX, and TEM. Finally, the stability of the photocatalysts was tested, and a potential photocatalytic reaction mechanism based on a Z-scheme heterojunction was proposed.