Ag-decorated ceramic silicate nanocomposites as dual-functional catalysts for hydrogen evolution reaction and organic pollutant reduction

HT/Ag nanocomposites were synthesized by combining the sol–gel method for hardystonite preparation with laser ablation in liquid to generate silver nanoparticles, followed by their in-situ incorporation. XRD, FTIR, FESEM, TEM, EDX, and XPS analyses confirmed the successful incorporation of Ag nanoparticles (20–27 nm) into the ceramic substrate, with a mixed Ag⁰/AgO surface composition. HER evaluation based on LSV measurements revealed that HT/Ag-7 exhibited the lowest overpotential of 180 mV at 10 mA cm⁻² and a Tafel slope of 78 mV dec⁻¹. In catalytic reduction experiments, HT/Ag-7 achieved complete degradation of methylene blue and Congo red in 2 min, and complete reduction of 4-nitrophenol in 5 min in the presence of NaBH₄. These findings suggest enhanced interfacial charge transfer, improved accessibility of catalytic interfaces, and synergistic interactions between silver nanoparticles and the hardystonite substrate.