Enhanced photoelectrocatalysis degradation of batik wastewater using Nitrogen-Doped Titanium Dioxide (TiO₂)

Batik is a significant textile industry in Indonesia, but it produces liquid waste containing azo dyes that are toxic and can pollute the environment. One approach to mitigate the impact of this waste is through TiO₂ photoelectrocatalysis. This study aims to improve the photoelectrocatalysis performance of TiO₂ by nitrogen doping, in order to achieve more efficient degradation of batik waste. This improvement is reflected in the increased intensity of the anatase phase, the reduction in band gap, and the formation of N-Ti-O bonds. N-doped TiO₂ was synthesized by anodizing titanium plates using urea at molar ratios of 50:50, 95:5, and 90:10, followed by annealing at 500°C for 3 hours. The results showed that the photoelectrocatalysis efficiency for the 90:10 TiO₂:urea ratio reached 90%, significantly higher than undoped TiO₂, which only degraded 50% of the batik waste. The band gap of N-doped TiO₂ was reduced to 2.7 eV, while undoped TiO₂ had a band gap of 3.2 eV. The formation of N-Ti-O bonds was also observed, confirming that nitrogen doping effectively enhances TiO₂'s ability to degrade batik waste through photoelectrocatalysis.