Sulfur quantum dot sensitized anatase TiO2 for enhanced photocatalytic activity

Abstract

Quantum dots exhibit unique photoconversion properties, making them attractive candidates for enhancing photocatalytic reactions. Nonetheless, it is rarely reported that sulfur quantum dot (SQD) sensitized TiO2. Furthermore, the lack of efficient synthetic approaches for high-throughput production of SQD remains a challenge in practical applications. Here, the sublimated sulfur powder was applied to achieve rapid and efficient synthesis of SQD by a two-step oxidation procedure. The method could avoid dialysis and freeze-drying processes while achieving a remarkable mass yield of up to 25% based on sulfur content. Product characterization suggested that the sulfonyl groups of SQD assisted in the attachment of SQD on TiO2 surface to form SQD-TiO2.The performance of SQD-TiO2 for degrading methyl orange in contaminated wastewater was assessed under simulated sunlight. The photocatalytic performance of SQD-TiO2 was significantly higher than that of pristine TiO2, suggesting excellent simulated sunlight photoconversion synergy between titanium dioxide as a photocatalyst and SQD as photosensitizers. The successful integration of SQD onto TiO2 would expend the effective utilization approaches of SQD in the field of photosensitizer.