具有可见光响应的磷烯/g-C3N4异质结的构建及其在高效太阳能分解水制氢中的应用

Construction of Phosphoene/g-C3N4 Heterojunction with Visible Light Response and Its Application in High Efficiency Hydrogen Production from Solar Water Splitting

近年来,二维(2D)g-C3N4基材料因其较短的电荷传输距离和充分暴露的表面活性位点,受到科研工作者的广泛关注。然而,g-C3N4较差的电荷分离和光吸收能力限制了进一步实际应用。通过引入具有高载流子迁移率和可见光响应的磷烯(FBP),构建FBP/g-C3N4异质结同时增强光催化剂的光吸收和电荷分离能力;同时,具有良好催化活性的FBP也可以作为g-C3N4的助催化剂,进一步降低电荷在催化剂/电解液界面处的反应势垒,从而有效抑制电荷复合,并提高光催化制氢效率。研究结果表明:相较于纯g-C3N4,FBP/g-C3N4异质结不仅可以有效抑制电荷复合、促进光生电荷分离,而且可以极大地拓宽光谱响应范围。最终,构建的FBP/g-C3N4异质结光催化剂获得了1.08 mmol·g^-1·h^-1的光催化制氢速率,相较于纯g-C3N4提高了1.2倍。

Recently,two-dimension g-C3N4 based materials have received tremendous attention,ascribing to its short charge diffusion distance and sufficiently exposed surface active sites.However,the poor charge separation and light harvesting still remains a great challenge for their practical applications.Herein,phosphorene/g-C3N4 heterojunction was constructed by simple introducing phosphorene which own visible light response and high mobility,to promote charge separation and light harvesting.Meanwhile,phosphorene can be regarded as effective co-catalyst for g-C3N4 to reduce the barrier of charge transfer between photocatalyst and electrolyte interface,and thus suppress charge recombination and improve photocatalytic hydrogen evolution rate.Compared to pure g-C3N4,the phosphorene/g-C3N4 heterojunction presents not only better charge separation and lower charge recombination,but also wider light response.As a result,the photocatalytic hydrogen evolution rate as high as 1.08 mmol·g^-1·h^-1 is achieved for phosphorene/g-C3N4 heterojunction,which is 1.2 times higher than the pure g-C3N4.