Broadband and strong visible-light driven photocatalytic enhancement utilizing two-dimensional plasmonics of Au/Cu-modified SrTiO3 perovskite nanostructures

Addressing limited access to clean drinking water demands innovative solutions to energy and environmental crises. Photocatalysis offers promise without eliciting secondary pollution, yet traditional metal oxide semiconductor photocatalysts encounter impediments in solar energy utilization and charge carrier recombination rates. To overcome these limitations, we present for the first time, a novel design, fabrication, and characterization of two-dimensional plasmonic noble metal/perovskite nanostructure hybrids for photocatalysis, combining Au as the plasmonic material with Cu-modified SrTiO3 as the semiconductor, fabricated on elastomeric polydimethylsiloxane substrates. Integrating localized surface plasmon resonance and Schottky junction-related band-bending significantly extends optical absorption into the ultraviolet-visible-infrared bands and enhances the effective carrier lifetimes, ensuring state-of-the-art photocatalytic efficiency. Exceptional photocatalytic performance in a 5-ppm aqueous methylene blue solution can be attained with 72.69-wt% Cu incorporation in the perovskite oxide, reaching a visible light-mediated photodegradation efficiency of 26% - an astounding 62.5-% efficiency increase compared to previous experiments without Cu modification. This advancement underscores the synergistic potential of noble metals and photocatalytic semiconductors in managing water purification challenges. •Metal-semiconductor nano-heterointerofaces confine holes to catalytic sites.•Charge transfer via LSPR and Schottky junction potential facilitated photocatalytic efficiency.•Cu doping of SrTiO3 enabled blueshift of plasmonically-enhanced absorption spectrum.•Surface plasmon resonance tuning via photonic crystal lattice constant optimized photocatalysis.•Plasmonic Au/Cu-SrTiO3-coated PDMS nanograting yielded 26-% MB dye decomposition.