The objective of this work was to utilize Zinc Oxide (ZnO) nanoparticles doped with 4 wt% Cu and varying concentrations of Fe (2, 3, 4, and 8 wt%) as efficient photocatalysts for dye degradation. The synthesized 2FCZ, 3FCZ, 4FCZ, and 8FCZ nanoparticles were tested on various dyes (Methylene Blue (MB), Rhodamine B (RhB), Rose Bengal (RB), Brilliant Yellow (BY), Acid Red (AR)) and their binary mixtures under artificial light and sunlight. Using 1 mg of catalyst and 1 mL of H2O2 for 100 mL of 10 ppm dye solution, 4FCZ showed the highest degradation efficiency. In an artificial reactor, it achieved 98.1 %, 94.8 %, 48 %, 65.6 %, and 21 % for the respective dyes, and in sunlight, 88.7 %, 75.3 %, 78.7 %, 52 %, and 27 %. 4FCZ demonstrated better performance in the artificial photoreactor. The catalyst’s selectivity was confirmed using binary dye mixtures, and its efficiency was attributed to the generation of radical dotOH radicals and inhibition of e−/h+ recombination. A key advantage is the minimal catalyst and H2O2 required, making this method promising for large-scale wastewater treatment, particularly in the textile industry.