TiO₂/TiO_xN_Y hollow mushrooms-like nanocomposite photoanode for hydrogen electrogeneration

Abstract

TiO₂/TiO_xN_y hollow mushrooms-like nanocomposite photocatalyst was prepared using atomic layer deposition (ALD) and reactive direct current magnetron sputtering, respectively. The preparation process depends on the aluminum oxide template (AOT) that was fabricated using the two-step anodization process after the Ni imprinting process. The chemical, morphological, and optical properties were recorded using different analyses such as XRD, SEM, EDX, and UV–Vis. From the SEM analyses, the AOT pore size increases from 177 to 305 nm after the pore widening process in H₃PO₄. The diameter of the TiO₂ in the upper part is 352 nm, while the diameter of the TiO₂/TiO_xN_y composite is 355 nm in the upper part. The estimated band gap values of TiO₂ and TiO₂/TiO_xN_y are 3.1 and 2.25 eV, respectively. From the values of band gaps, there is a clear enhancement in the optical absorption of the nanocomposite bilayers. The photoelectrochemical (PEC) behaviors of the TiO₂/TiO_xN_y electrodes supported in Au/Ni metal thin film was measured in 1 M NaOH as scarifying reagent. The thermodynamic parameters were calculated, in which ΔE, ΔH*, and ΔS* values are 16.75 kJ mol⁻¹, 15.87 kJ mol⁻¹ and − 115.65 kJ mol⁻¹ K⁻¹, respectively.