Photocatalytic generation of hydrogen under visible light on La2CuO4

Bulletin of materials science

H Lahmar¹  M Trari¹ 

[1] Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry (USTHB), B.P. 32, 16111 Algiers, Algeria$$Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry (USTHB), B.P. 32, 16111 Algiers, AlgeriaLaboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry (USTHB), B.P. 32, 16111 Algiers, Algeria$$

关键词: La2CuO4;    optical transition;    photo-electrochemical;    electrochemical impedance spectroscopy;    hydrogen.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The semiconducting properties of La₂CuO₄ prepared by a chemical route are investigated for the first time by the photo-electrochemical technique. The optical gap is found to be 1.27 eV and the transition is directly allowed. p-Type conductivity is demonstrated from the Mottâ€�?�Schottky plot in alkaline KOH solution (0.1 M), extrapolation of the linear region to the potential axis gives a flat band potential of âˆ�?0.41 V_SCE, a holes density of 1.75 Ã�? 10¹⁹ cm^âˆ�?3 and a space-charge region of 18 nm. The electrochemical impedance spectroscopy, measured over the frequency range (1 mHzâ€�??10⁵ Hz), reveals the predominance of the bulk contribution with a constant phase element. The energy diagram shows the feasibility of La₂CuO₄ for the H₂ evolution under visible light. The best performance occurs at pH 12.5 in the presence of S₂O$^{2-}_{3}$ as holes scavenger. A liberation rate of 20.6 𝜇mol mn^âˆ�?1 (g catalyst)^âˆ�?1 is obtained under full light (29 mW cm^âˆ�?2).

【 授权许可】

Unknown