Novel visible light responsive materials for water splitting are essential for the efficient conversion of solar energy into hydrogen bond energy. Among other semiconductors, gadolinium orthovanadate has appropriate conduction and valence band edges positioned to split water molecules and a narrow band gap that allows the use of visible light for hydrogen generation. Thus, we present here that hydrogen evolution under visible light (λ > 420 nm) could be accomplished using hierarchical 3D GdVO₄ particles, obtained by a simple, one pot hydrothermal synthesis. We found that applying various reaction components, such as EDTA-Na₂ and EDTA, and adjusting the pH of the solution allow one to tune the shape of GdVO₄ (such as short nanowires, long nanowires, short nanorods, long nanorods, nanoparticles and spheres – all having a tetragonal crystal structure) as well as optical and photocatalytic properties. The highest ability to photocatalytically split methanol solution into hydrogen under UV-Vis irradiation was detected for the long nanowire sample (42 μmol h⁻¹), having almost 11 times higher efficiency in comparison with the weakest sample – short nanowires. In addition, GdVO₄ spheres generated H₂ more than 2 times (5.75 μmol h⁻¹) in comparison with the short nanorod sample (2.5 μmol h⁻¹) under visible light excitation. Photostable in three-hour work cycles, long nanowires and spheres were even able to generate hydrogen from pure water, reaching values of 17 and 3 μmol under UV-Vis and Vis light, respectively.

Antibiotics are extensively used in human medicine, aquaculture, and animal husbandry, leading to the release of antimicrobial resistance into the environment. This contributes to the rapid spread of antibiotic-resistant genes (ARGs), posing a significant threat to human health and aquatic ecosystems. Conventional wastewater treatment methods often fail to eliminate ARGs, prompting the adoption of advanced oxidation processes (AOPs) to address this growing risk. The study investigates the efficacy of visible light-driven photocatalytic systems utilizing two catalyst types (TiO₂-Pd/Cu and g-C₃N₄-Pd/Cu), with a particular emphasis on their effectiveness in eliminating bla_TEM, ermB, qnrS, tetM. intl1, 16 S rDNA and 23 S rDNA through photocatalytic ozonation and peroxone processes. Incorporating O₃ into photocatalytic processes significantly enhances target removal efficiency, with the photocatalyst-assisted peroxone process emerging as the most effective AOP. The reemergence of targeted contaminants following treatment highlights the pivotal importance of AOPs and the meticulous selection of catalysts in ensuring sustained treatment efficacy. Furthermore, Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analysis reveals challenges in eradicating GC-rich bacteria with TiO₂ and g-C₃N₄ processes, while slight differences in Cu/Pd loadings suggest g-C₃N₄-based ozonation improved antibacterial effectiveness. Terminal Restriction Fragment Length Polymorphism analysis highlights the efficacy of the photocatalyst-assisted peroxone process in treating diverse samples.