A green approach: scalable dry media synthesis of a γ-TaON photocatalyst for solar H2production and rhodamine B degradation

Extending the light absorption range and facilitating the separation of photo-induced charge carriers are effective strategies to improve the performance of the photocatalytic process. Here, we report a new, scalable and low temperature solid state method for the synthesis of different TaON polymorphs. Tantalum oxynitride (TaON), a visible light active photocatalyst, was investigated for photocatalytic H(2)production as well as degradation of Rhodamine B under artificial solar light (Xe lamp) and natural sunlight. XPS confirms substitutional (N-s) as well as interstitial (N-i) nitrogen incorporation into the Ta(2)O(5)lattice. Optical characterization reveals a red shift in absorption from the UV to visible region for TaON samples. XRD confirms the crystalline phase of different polymorphs of TaON such as gamma, beta etc.The results of the photocatalytic activity of the synthesized catalysts for hydrogen (H-2) productionviaH(2)O splitting and degradation of the Rhodamine B pollutant show that among the series of synthesized catalysts, the pure gamma-TaON phase displays the highest H(2)production of 1393.6 mu mol per 0.1 g per hour under natural solar light, whereas under similar experimental conditions 833.6 mu mol per 0.1 g hour under a xenon lamp using triethanolamine as a sacrificial electron donor is observed. Likewise, the synthesized gamma-TaON photocatalyst decomposes 99.8% of 10 ppm Rhodamine B solution in just 100 min under natural solar light.