Influence of stress on physical properties of CsGaO3 for enhanced photocatalytic application: A DFT perspective

Abstract

The dual threat of water contamination and energy resource depletion has prompted increased research into hydrogen as a green energy source. However, its evolution and storage remain problematic. To address this, researchers are focusing on perovskite hydrides, known for their strong ion exchange abilities and impressive storage capacity by weight. Dealing with severe energy crisis and water contamination, we have performed the calculations for our considered compound CsGaO₃ at different pressure from 0 GPa to 18 GPa by employing the GGA-PBE approach by using first principles computational method, using density functional theory (DFT) via CASTEP to address this issue. We have computed the structural, photocatalytic, electronic, optical, mechanical, phononic and thermodynamic properties of CsGaO₃ under the considered stress range of 0 GPa–18GPa. From the structural analysis it is confirmed that no phase transition occurs and CsGaO₃ possess cubic behavior at all the pressures. The thermodynamic sustainability of our considered material is confirmed by the negative formation energy, free energy, entropy and heat capacity etc. Under considered stress a continuous decrease in lattice constants and an increase in band gap (1.501eV–2.904eV) is inspected up to 18 GPa. For a thorough assessment of band gap, EPDOS and TDOS have also been conclude. It is concluded from the electronic properties that at 18Gpa, our tuned band gap is most suitable for the photocatalytic water splitting application in visible range under solar radiations. For quick response to incoming photons, good absorption and extinction coefficient are key parameters. From calculated optical parameters we come to know that our compound at considered pressure possess excellent absorptive properties for its utilization in photocatalysis. Its mechanical stability is confirmed by the elastic constants in GPa. We come to know from the estimated parameters that, brittleness decline as the pressure is being applied and our compound possess ductile nature at considered pressure which increases its impact for the application of photocatalytic water splitting. Anisotropic nature of CsGaO₃ is observed in anticipated outcomes. At the end we have calculated phonon dispersion curve and density of state to confirm its dynamical stability. According to our computed results, our compound is perfectly dynamically stable which provides an exceptional favor to use it in photocatalytic water splitting application and hydrogen evolution.