Fabrication of Ag‐photodeposited TiO2/cordierite honeycomb monolith photoreactors for 2‐naphthol degradation

BACKGROUND Polycyclic aromatic hydrocarbons and their derivatives have harmful effects on organisms and the environment. As a typical polycyclic aromatic hydrocarbon, 2‐naphthol is a persistent, highly toxic organic pollutant that biodegrades very slowly and thus its elimination is of high priority. RESULTS Ag‐deposited TiO2/cordierite honeycomb monoliths (CHMs) have been successfully applied to the photocatalytic degradation of 2‐naphthol. The physical properties of the catalyst were characterized using various techniques. Deposition of metallic silver on a thin layer of TiO2 adhering to the inner walls of the CHM reduces the bandgap energy and lowers the recombination rate of photogenerated electrons and holes. The optimal photocatalyst (0.4Ag‐deposited S700‐ST) exhibits a first‐order degradation rate of k = 0.048 min−1 with 91.0% decomposition of 2‐naphthol after 240 min of irradiation with 12 W, 395 nm LED light. The 0.4Ag‐deposited S700‐ST material is stable throughout four photocatalytic reaction cycles. CONCLUSIONS The work presented describes the development of a robust, stable TiO2‐coated CHM that overcomes the recovery drawbacks of nano‐TiO2‐based slurries in photocatalytic wastewater treatment. © 2020 Society of Chemical Industry