RESUMO
The nanoflakes of SnS2/SnO2heterostructure and SnS2were synthesized by a one-step SnO2-templated chemical vapor deposition method. The metal oxide-assisted growth mechanism of SnS2/SnO2heterostructure and SnS2nanoflakes were realized through investigating serial microstructures of products with varied growth time. Furthermore, the photocatalytic activity for MB dyes degradation of varied growth time products was used to explore the effect of product microstructure under the visible light irradiation. The SnO2/SnS2heterostructure and the oxide vacancies of nanoflakes demonstrated an improved visible light photocatalytic performance for MB degradation, which was around twice of the pure SnS2nanoflakes and better than P25. The results of different scavengers on the degradation efficiency for MB indicate the·O2-, and ·OH are the main active species in the photodegradation reaction. The one-step growth mechanism of SnS2/SnO2could prove a facile process to grow metal oxide-metal sulfide heterostructure.
RESUMO
Inorganic perovskite quantum dots (IPQDs) such as cesium lead halide (CsPbX3, X = Cl, Br and I) quantum dots have attracted much attention for developing cadmium-free quantum light-emitting displays (QLEDs) based on outstanding light emission properties including narrow full width at half maximum (FWHM), tunable bandgap and ultrahigh (>90%) photoluminescence quantum yield (PLQY). Nevertheless, their poor stability under ambient conditions, at high temperature or under continuous light irradiation is the main problem for practical applications. In this study, a new method is proposed to effectively stabilize CsPbBr3 IPQDs by synthesizing them with sulfate-functionalized cellulose nanocrystals (CNCs) at room temperature without using traditional quantum dot stabilizers such as oleylamine (OLA) and oleic acid (OA). The as-prepared CsPbBr3 IPQD/CNC hybrid paper-like films are highly stable and the relative photoluminescence (PL) intensity can be maintained at 92% under continuous UV light (306 nm, 15 W) illumination for 130 h, >99% at high temperature (100 °C) for 130 h, and >99% in ambient conditions for 15 d. Additionally, the PLQY and FWHM of IPQD/CNC are 45.69% and 22 nm, respectively. The ultrahigh stability and narrow FWHM characteristics proposed here for IPQD/CNC hybrid films can provide new possibilities for practical applications in the future development of IPQD-related devices.
