Praseodymium orthovanadate-waste PET bottle derived sulfur doped carbon for efficient Z-scheme photocatalytic CO2 reduction

Abstract

Escalating amounts of carbon dioxide (CO2) in the Earth's atmosphere are a major cause of climate change and its negative consequences, making it a global concern. The present work highlights the intersection of waste management, resource utilization, and climate change mitigation, showcasing the potential for an additional sustainable and circular economy. Synthesizing carbon from waste polyethylene terephthalate (PET) bottles is an eco-friendly approach. X-ray diffraction, Raman spectroscopic, scanning electron microscopic, tunnelling electron microscopic, infrared fourier transform spectroscopy (FTIR) and X-ray photoelectron spectroscopic results indicate the effective extraction of carbon doped with sulfur (S@C) and the successive formation of nanocomposite with PrVO4 (PrV/S@C). Superior photocatalytic activity was observed under visible light compared to UV light. PrV/S@C showed enhanced light-driven CO2 reduction compared to pristine materials and was found to evolve 39, 56, and 98 µmol h−1 g−1 of H2, CH4 and CO, respectively. The effect of reaction temperature was examined and optimized at 100 °C. The enhanced activity in PrV/S@C compared to PrV and S@C probably due to the increased surface area, conductivity and synergy. In-Situ Diffused reflectance (DRIFT-IR) and liquid chromatography mass spectroscopy (LC-MS) confirm the evolution of CO and CH4. The optical, photo/electrochemical, Scavenger studies, Electron spin resonance (ESR) and Mott-Schottky studies suggest the formation of a direct Z-scheme photoredox reaction in the presence of PrV/S@C and sacrificial gent. The reusability studies for 5 cycles indicate good stability with a slight deviation in structure and morphology of PrV/S@C, as observed in XRD and SEM. Tackling plastic pollution and generating value-added carbonaceous products through CO2 reduction is the twin application of the present work that has piqued the interest of several researchers in environmental remediation.