Embedding Cu3P quantum dots onto BiOCl nanosheets as a 0D/2D S-scheme heterojunction for photocatalytic antibiotic degradation

The development of highly efficient photocatalysts is vital for solvinge the problem of environmental pollution. In this study, a novel zero-/two-dimensional (0D/2D) S-scheme heterojunction was fabricated by integrating 0D copper phosphide (Cu3P) quantum dots (QDs) with a size in the range of 3-8 nm onto 2D bismuth oxychloride (BiOCl) nanosheets using a self-assembly tactic. The Cu3P/BiOCl presented intimate interface contact and high photocatalytic activity for the degradation of antibiotics (tetracycline hydrochloride (TC), oxytetracycline, ofloxacin). The optimal sample exhibited the highest photocatalytic TC degradation, with a total removal rate of 86% after 6 min under full-spectrum irradiation, which was higher than that of compared to individual BiOCl. The improved activity of the Cu3P/BiOCl heterojunction was attributed to the enhanced separation of the photogenerated carriers due to the S-scheme mode which can promote the recombination of useless photogenerated carriers and maintain photogenerated carriers with stronger redox potentials for photocatalytic reaction. In addition, employing Cu3P QDs and BiOCl nanosheets to construct an S-scheme composite can offer abundant active sites for antibiotic degradation. In brief, this study demonstrates that Cu3P QDs are an effective cocatalyst for degrading organic pollutants, which provides novel inspiration for the future design of green recycling photocatalysts for wastewater remediation.