Hydrothermally synthesized Cu/TiO ₂ /SAPO-34 with superior photoelectrochemical properties for pharmaceutical and organic pollutant degradation

Abstract

This study presents the synthesis of a chabazite photocatalyst (Cu/TiO₂/SAPO-34) using an innovative hydrothermal method for the rapid degradation of pharmaceutical and organic pollutants. The material was characterized using scanning electron microscope, energy dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance, and photoluminescence spectroscopy for morphology, structure, molecular bonding, and optical properties. The Cu/TiO₂/SAPO-34 was photoelectrochemically characterized using linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), Photocurrent (PC) transient curves, and Mott–Schottky (MS) analysis. The pharmaceutical and organic pollutant removal ability of the photocatalyst was investigated through a paracetamol and methylene blue photodegradation test, using ultraviolet radiation. The Cu/TiO₂/SAPO-34 photocatalyst exhibited superior electrochemical, light absorption, structural, and photocatalytic properties compared to TiO₂. It demonstrated reduced charge transfer resistance (2007 vs. 3931 Ω), higher photocurrent density (46 vs. 9 μA/cm 2 ), and improved charge migration and optically generated charge carrier separation, leading to improved photoelectrochemical performance. Structural analysis confirmed the formation of the composite with a larger average crystallite size (17.56 vs. 13.11 nm for TiO 2 ). FTIR and EDX analyses verified the presence of Cu, TiO 2 , and SAPO-34 in the mix. Optical analysis showed reduced bandgap energy (2.61 eV vs. 3.09 eV for TiO 2 ), enhanced UV and visible emissions, and early infrared absorption. The composite outperformed TiO 2 in degrading pharmaceutical and organic contaminants, showcasing its potential for advanced photocatalytic and photoelectrochemical applications. The material can suppress biodegradation, preserve the natural world, enhance solar energy absorption, self-clean medical equipment, and purify wastewater from pharmaceutical contaminants.