Green Approach: Scalable Dry Media Synthesis of γ-TaON Photocatalyst for Solar H2 Production and Rhodamine B Degradation
Extending the light absorption range and facilitating the separation of photo-induced charge carriers is an effective strategy to improve the performance of photocatalytic process. Here, we are reporting a new, scalable and low temperature solid state method for the synthesis of different TaON polymorphs. Tantalum oxynitride (TaON) a visible light active photocatalyst investigated for photocatalytic H2 production as well as degradation of Rhodamine B under artificial solar light (Xe lamp) and natural sunlight. XPS confirms substitutional (Ns) as well as interstitial (Ni) nitrogen incorporation into Ta2O5 lattice. Optical characterization reveals red shift in absorption from UV to visible region for TaON samples. XRD confirms the crystalline phase of different polymorphs of TaON such as γ, β etc. The results of photocatalytic activity of synthesized catalysts for the hydrogen (H2) production via H2O splitting and degradation of Rhodamine B pollutant show that, among the series of synthesized catalyst, pure γ-TaON phase displays highest H2 production of 1393.6 μmol/0.1g/hr under natural solar light, whereas at similar experimental condition 833.6 μmol/0.1g/hr under xenon lamp using triethanolamine as a sacrificial electron donor. Likewise, synthesized γ-TaON photocatalyst decomposes 99.8% of 10 ppm Rhodamine B solution in just 100 min under natural solar light.