The materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and Ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic activity of CN-500/TaO-W samples was assessed by degradation of methylene blue in aqueous solution under visible light. Among them, CN-500/TaO-4 exhibited the best performance. An enhancement in photocatalytic activity of the composites is believed to be the presence of g-C3N4. | Vietnam Journal of Chemistry, International Edition, 55(2): 172-177, 2017 DOI: The photocatalytic activity of g-C3N4/Ta2O5 composite under visible light irradiation Nguyen Thi Viet Nga1*, Vo Vien1,2 1 Department of Chemistry, Quy Nhon University 2 Applied Research Institute for Science and Technology, Quy Nhon University Received 28 February 2017; Accepted for publication 11 April 2017 Abstract The g-C3N4/Ta2O5 composites were synthesized by heating mixtures of urea and Ta2O5 at 500 oC. The as-prepared samples were denoted as CN-500/TaO-W, where W is weight ratio of urea/Ta2O5 and equals to 3, 4 and 5. The materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and Ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic activity of CN-500/TaO-W samples was assessed by degradation of methylene blue in aqueous solution under visible light. Among them, CN-500/TaO-4 exhibited the best performance. An enhancement in photocatalytic activity of the composites is believed to be the presence of g-C3N4. Keywords. g-C3N4, Ta2O5, photocatalytic activity, methylene blue, g-C3N4/Ta2O5 composite. 1. INTRODUCTION The study of materials that could absorb light from the sun to decompose organic pollutants in water and air is not only an opportunity but also a challenge for many researchers and attracts a lot of interest from society. The semiconductors that highly exhibit the catalytic performance under light have been known as potential photocatalysts. They possess many advantages including high efficiency in conversion of solar energy, strongly catalytic activity, highly capable decomposition of organic pollutants, reusability and especially environmental friend. Among the semiconductors, in recent years, Ta2O5 has attracted much attention in photocatalysis. However, with the large band gap energy (about to eV), its photocatalytic activity only exhibits in ultraviolet region [1], leading to .
