Eu³⁺:Y<inf>2</inf>Ti<inf>2</inf>O<inf>7</inf> nanomaterials as efficient photocatalysts used for hydrogen and biogas production toward a sustainable environment

Abstract

The main focus of this research is on energy production by clean photocatalytic technology. By using the sol–gel process, yttrium titanate nano-photocatalysts modified with europium (x mol. Eu3+:Y2Ti2O7) have been created and used to produce photocatalytic biogas and hydrogen using acetic acid. X-ray powder diffraction (XRD) confirms the formation of cubic Y2Ti2O7 phase. Microscopic study has indicated that Eu doping improved the shape, size, and dispersity of Y2Ti2O7 photocatalyst. Different crystal defects, including oxygen vacancies (OVs) and Ti3+ species, are demonstrated by X-ray photoelectron spectroscopy (XPS) studies. Compared with pure Y2Ti2O7, 0.03 mol. Eu3+:Y2Ti2O7 has the highest proportion of lattice defects. The band gap energies have increased as a result of doping on Y2Ti2O7 size. Urbach energy calculations confirm that Eu3+:Y2Ti2O7 nano-photocatalyst has the highest degree of distortion. The photoluminescence (PL) measurements have shown that 0.03 mol. Eu3+ dopant can effectively separate the active charge carriers. Electron spin resonance proved the progressive increase of defect states (OV and Ti3+) by doping, which promoted the photocatalytic activity of the nano-photocatalyst. These photocatalysts have generated biogas and hydrogen gas via photocatalytic oxidation of acetic acid under inert conditions. The maximum photocatalytic activity for the generation of biogas and hydrogen is found in 0.03 mol. Eu3+:Y2Ti2O7. The maximum photocatalytic activity of 0.03 mol. Eu3+:Y2Ti2O7 is correlated with higher lattice defects (OV, Ti3+) and reduced charge carrier recombination. The proposed photocatalytic mechanism has been discussed. According to the findings, Eu3+:Y2Ti2O7 nano-photocatalyst is a promising nanomaterial for the generation of energy.