Boosting photocatalytic efficiency through Ni–Co co-doped ZnO thin films fabricated by spray pyrolysis

Ni–Co co-doped ZnO thin films were synthesized on glass substrates via the spray pyrolysis technique to investigate the synergistic effect of dual doping on photocatalytic performance. The incorporation of Ni and Co ions effectively modified the structural, morphological, and optical properties of ZnO, as confirmed by XRD, SEM, AFM, EDX, and UV–vis spectroscopy. Photocatalytic tests under sunlight irradiation showed a remarkable enhancement in methylene blue degradation for Ni–Co co-doped ZnO films. In particular, 1.5 % Ni–Co co-doped ZnO achieves a 95 % degradation efficiency after 180 min of sunlight exposure. • Ni–Co co-doped ZnO thin films are synthesized by the spray pyrolysis technique. • The incorporation of Ni and Co ions modifies the structural, morphological, and optical features of the host lattice. • Photocatalytic experiments demonstrate that co-doped films outperform undoped and singly doped ZnO. • Ni–Co co-doping is an effective strategy to engineer ZnO films with superior photocatalytic and optoelectronic properties.