In-situ self-assembly of Z-scheme TiO2/g-C3N4 heterojunction enhanced visible-light photocatalytic performance for degrading phenolic pollutants

In recent years, eliminating impurities from wastewater has become increasingly crucial. Photocatalytic technology has become a viable strategy for degrading organic pollutants. This study created novel Z-scheme TiO 2 -modified g-C 3 N 4 using a solvent-tunable, two-step method. The optimized TiO 2 /g-C 3 N 4 -Et/vis system demonstrated a removal efficiency of 94.4 % for acetaminophen (ATP) within 40 min and 91.0 % for methylparaben (MPB) within 100 min. Furthermore, the system maintained 92.7 % ATP degradation efficiency after five cycles, indicating excellent recoverability and sustainability. Photochemical tests and mechanistic studies revealed that solvent modulation and TiO 2 modification increased the specific surface area and facilitated the formation of Z-scheme heterojunctions. These heterojunctions effectively inhibit the recombination of photogenerated electron-hole pairs and enhanced the degradation efficiency of organic pollutants, primarily driven by •O 2 − . LC-MS analysis found the intermediates of ATP and MPB, and several potential routes of degradation were suggested. This work sheds fresh light on the production of high-performance TiO 2 /g-C 3 N 4 nanoparticles for applications related to energy and the environment.