Type-II TiO2/CoAl-LDH heterojunction enabling fast H2O2-assisted UV decolorization of complex dyeing effluent

Photocatalytic technology offers a promising solution for degrading organic pollutants in wastewater. However, catalysts often suffer from limited light absorption and rapid electron-hole recombination. To address the challenges, we developed a heterogeneous TiO 2 /CoAl-LDH catalyst for photocatalytic degradation of dyes such as Acid fuchsin (AF) and methyl orange (MO) and real wastewater under UV light irradiation. The aligned band structures of TiO 2 and LDH enhanced UV light energy absorption and electron-hole separation, resulting in superior photocatalytic activity. In treating real dyeing wastewater, TiO 2 /CoAl-LDH + H 2 O 2  + UV achieved higher decolorization than UV/H 2 O 2 or catalyst/H 2 O 2 alone under the same operating conditions. The process within the early stage (0–45 min) followed pseudo-first-order kinetics (kₐₚₚ ≈ 1.50 × 10 −2  min −1 ), with a clear H 2 O 2 optimum at 40.8 mM. Excitation–emission matrix (EEM) fluorescence showed rapid quenching of protein-like (B/T) and humic/fulvic-like (A/M/C) peaks with blue-shifts under the TiO 2 /CoAl-LDH + H 2 O 2  + UV condition corroborating deeper oxidation and mirroring the ADMI decolorization trend (fast loss of B/T within 15 min, followed by progressive depletion of humic-like emission). This study presents a simple and cost-effective method for developing efficient hierarchical semiconductor materials potentially applicable as photocatalysts for wastewater treatment.