TiO2/BP/g-C3N4 heterojunction photocatalyst for the enhanced photocatalytic degradation of RhB.

Abstract

The efficiency of graphite carbon nitride (g-C3N4, CN) as a photocatalyst is limited due to its quick recombination of photogenerated carriers and layer re-stacking. To enhance its photocatalytic activity, a multi-heterojunction photocatalyst was developed using TiO2 and black phosphorus (BP) coupled with CN through a liquid-phase ultrasonic method. The composite, TiO2/BP/CN, demonstrated a wider range of light response and higher photo-induced carrier separation efficiency. The presence of TiO2 nanoparticles on CN nanolayers reduced interlayer stacking and increased specific surface area, thereby providing more reactive sites. As a result, the optimized TiO2/BP/CN composite demonstrated enhanced photocatalytic efficiency for the degradation of Rhodamine B (RhB), with a first-order kinetic constant of 2.8, 4.3, and 6.4 times that of CN, TiO2, and BP, respectively. Active substance capture experiments confirmed that superoxide radical (·O2) was the primary reactive species. This study highlights the potential of the developed TiO2/BP/CN composite as a promising photocatalyst for environmental remediation applications.