Bismuth oxychloride microcrystals decorated carbon foams based on waste polyurethane elastomer for enhanced removal of methylene blue

Abstract

Multicomponent materials containing nanoscale structures, the so-called “nanocomposites” are one of the fastest-growing areas of photocatalytic research. In this study, the nanocomposites of bismuth oxychloride (BiOCl) with porous carbon foam (CF) derived from waste polyurethane (PU) elastomers were developed by a simple hydrothermal method, and the photocatalytic performance of the as-prepared materials was investigated. The structure, morphology and optical properties of the composites were characterized in detail. The photocatalytic activity of the samples was evaluated by studying the degradation of methylene blue (MB) under UV-A irradiation. Even at a high MB concentration (0.5 mmol/L), excellent photocatalytic activity was observed, with an overall removal efficiency of 99.0% in 100 min of irradiation. Kinetic studies were also carried out for the degradation of MB by pristine BiOCl and CF-BiOCl. The photodegradation rate constants were evaluated by fitting the kinetic data with a pseudo-first-order model, and the rate constants of CF-BiOCl composites were higher than that of pristine BiOCl. The enhanced activity of the composites was due to the well-connected heterojunction interface, improved hydrophilicity, more reactive sites, and effective separation of photo-generated charges. Thus, our work combines the valuable waste PU-derived CFs with BiOCl, which provides a strategy to achieve circular economy and environmental remediation objectives.