Work

Morphology-engineered Ag/ZnO coral-like nanoplates for visible-light photocatalytic degradation of methyl orange and decolorization of palm oil mill effluent

Year: 2026

Type: article

Abstract: a urea-assisted hydrothermal method and Ag-modified ZnO was prepared by introducing silver nitrate into the precursor mixture prior to hydrothermal treatment to enhance visible-light photocatalytic activity. The effects of urea concentration and Ag loading on the morphology, surface characteristics, optical properties, and photocatalytic performance of the materials were systematically investigated. Among the pristine ZnO samples, ZnO-16U exhibited the highest photocatalytic activity, achieving approximately 90% methyl orange (MO) degradation under UV irradiation after 120 min despite having the lowest BET surface area, indicating that photocatalytic performance was governed by a combination of structural accessibility and optical/electronic properties. Ag incorporation markedly enhanced visible-light activity, with 5 wt% Ag/ZnO achieving approximately 92% MO degradation and 85% decolorization of post-treated POME after 120 min. For post-treated POME, 5 wt% Ag/ZnO also achieved 83% COD removal and 82% TOC removal, demonstrating substantial reduction of the residual organic load. The enhanced activity was associated with improved visible-light absorption through Ag-induced localized surface plasmon resonance and more efficient interfacial charge separation within the Ag/ZnO heterostructure. The 5 wt% Ag/ZnO catalyst retained approximately 79% POME decolorization after five reuse cycles, while very low Ag and Zn leaching indicated good material stability during repeated operation. The results demonstrate that combining morphology-engineered ZnO with Ag modification provides an effective strategy for developing visible-light-responsive photocatalysts for dye-contaminated water and post-treated POME from palm oil milling operations.

Source: RSC Advances

DOI: 10.1039/d6ra06010b

Authors: Piangjai Peerakiatkhajohn, Teera Butburee, Miaoqiang Lyu, Salwatee Yu-soh, Padsiriporn Budwang, Supphasin Thaweesak