CsPbBr₃@TiO₂ Core-shell Structure Nanocomposite as Water Stable and Efficient Visible-light-driven Photocatalyst

Abstract

The inherent poor stability of CsPbBr 3 perovskite quantum dots (QDs) is the main impediment restricting their applications. In this work, a CsPbBr 3 @TiO 2 core-shell structure nanocomposite with high water stability and efficient photocatalytic activity was fabricated through the hydrolysis of tetrabutyl titanate, followed by calcination. The as-prepared CsPbBr 3 QDs have a size of ca. 8 nm, encapsulated by incompletely crystallized TiO 2 protective layer with a thickness of ca. 20 nm. The photocatalytic performance of the CsPbBr 3 @TiO 2 nanocomposite was investigated by degradation of Rhodamine B (RhB) in water under visible light irradiation. The result shows that the CsPbBr 3 @TiO 2 nanocomposite exhibits much more enhanced photocatalytic activity than pure TiO 2 and CsPbBr 3 perovskite quantum dots. The photocurrent test results showed that the formation of the CsPbBr 3 @TiO 2 heterostructure can promote the separation of photogenerated carriers, which led to the improvement of photocatalytic performance of the composite material. More importantly, TiO 2 can act as a protective layer

Recent Progress in Halide Perovskite Nanocrystals for Photocatalytic Hydrogen Evolution

“…Recently, halide perovskite materials—on account of their fascinating electronic and optical properties, including outstanding visible light harvesting ability, suitable band positions to provide sufficient driving potential, as well as their high carrier mobility and long electron-hole diffusion lengths—have emerged as a class of promising candidates for photocatalytic applications. To date, various kinds of halide perovskites, in either an organic–inorganic or all-inorganic fashion (e.g., CH 3 NH 3 PbX 3 , CsPbX 3 , X = Cl, Br, I), have shown great potential in photocatalysis fields such as CO 2 reduction [ 34 , 35 , 36 , 37 , 38 , 39 , 40 ], hydrogen generation [ 41 , 42 , 43 , 44 , 45 ], pollutant degradation [ 46 , 47 , 48 , 49 , 50 , 51 ], phemethylol oxidation [ 52 , 53 ], organic reaction [ 54 , 55 ], etc. Since the first demonstration of using methylammonium lead iodide (CH 3 NH 3 PbI 3 , MAPbI 3 ) for hydrogen generation via the solar-driven splitting of hydrogen iodide by Park et al [ 44 ], the potential of halide perovskites for photocatalytic hydrogen production has been investigated by many researchers.…”