Designed construction of boosted visible-light Z-scheme TiO2/PANI/Cu2O heterojunction with elaborated photocatalytic degradation of organic dyes

Abstract

A novel TiO2/polyaniline/Cu2O (T/PANI/Cu) ternary nanocomposite was synthesized via a facile in-situ polymerization of aniline and a one-step solvothermal method. The ternary nanocomposite Ti/PANI/Cu with Z-scheme heterojunction exhibited excellent photocatalytic performance as well as improved stability. The photocatalytic performance of the prepared photocatalysts (T, T/PANI, and T/PANI/Cu) was investigated by the photocatalytic decomposition of Methyl Orange dye (MO) as an organic contaminant using visible light illumination. The T/PANI/Cu ternary nanocomposite revealed the highest degradation efficiency up to 99.5% after 25 min, which is much higher than that of T (47%) and T/PANI (73%). The development of Z-scheme heterojunction is credited with the increased activity and generation of an electric field that led to an improved structure, a wider visible light response range, and a lower rate of electron-hole pair recombination. Based on trapping tests, ·O2−·OH, and h+ species were the main active species involved in the photocatalytic degradation of MO dye. Even after the fifth cycle, the T/PANI/Cu composite remained effective in the successive photocatalytic decomposition of MO, maintaining over 90% of the original degradation efficiency.