Comparison of photocatalytic activity of Cu/TiO2, Cu/NiO and Cu/ZnO nanocomposites for the degradation of organic dyes
Rezvaneh Amrollahi
Abstract
The removal of organic pollutants from water presents a significant challenge in environmental engineering. This research synthesized nanometal oxides, titanium dioxide, nickel oxide, and zinc oxide modified with copper (Cu) using a straightforward solvothermal method. Introducing 3 wt% Cu nanoparticles effectively activated these transition metal oxides within the visible light spectrum. The resulting nanocomposites (NCs) underwent evaluation for their ability to photocatalytically degrade methyl orange (MO) and methylene blue (MB) dyes at concentrations of 10, 20, and 30 mg/L, under LED and xenon lamps with varying wavelengths and intensities, impacting the degradation process. Characterization of the NCs was conducted using SEM, EDS, BET, XRD, FTIR, and DRS analyses. Results demonstrated that the synthesized nanocomposites were more efficient in degrading MB compared to MO. Notably, the Cu/TiO 2 NCs outperformed the others, achieving photodegradation rates of 88 % for MB and 74 % for MO. The findings indicate that Cu-enhanced transition metal oxide NCs hold promise as effective photocatalysts for water purification. • A new method for creating Cu-doped metal oxides significantly enhances photocatalytic dye degradation in water. • The addition of 3 wt% Cu nanoparticles markedly improves dye removal efficiency under visible light. • Advanced techniques confirm Cu nanoparticles' uniform distribution and metal oxides' purity, essential for photocatalysis. • TiO 2 /Cu nanocomposites show the highest rates for degrading dyes, following a pseudo-first-order kinetic model. • The nanocomposites remain effective over multiple cycles, promising sustainable water purification solutions.