Search

2D Ti3C2Tx MXene, possessing facile preparation, high electrical conductivity, flexibility, and solution processability, shows good application potential for enhancing device performance of perovskite solar cells (PVSCs). In this study, tetrabutylammonium bromide functionalized Ti3C2Tx (TBAB‐Ti3C2Tx) is developed as cathode buffer layer (CBL) to regulate the PCBM/Ag cathode interfacial property for the first time. By virtue of the charge transfer from TBAB to Ti3C2Tx demonstrated by electron paramagnetic resonance and density functional theory, the TBAB‐Ti3C2Tx CBL with high electrical conductivity exhibits significantly reduced work function of 3.9 eV, which enables optimization of energy level alignment and enhancement of charge extraction. Moreover, the TBAB‐Ti3C2Tx CBL can effectively inhibit the migration of iodine ions from perovskite layer to Ag cathode, which synergistically suppresses defect states and reduce charge recombination. Consequently, utilizing MAPbI3 perovskite without post‐treatment, the TBAB‐Ti3C2Tx based device exhibits a dramatically improved power conversion efficiency of 21.65% with significantly improved operational stability, which is one of the best efficiencies reported for the devices based on MAPbI3/PCBM with different CBLs. These results indicate that TBAB‐Ti3C2Tx shall be a promising CBL for high‐performance inverted PVSCs and inspire the further applications of quaternary ammonium functionalized MXenes in PVSCs. [ABSTRACT FROM AUTHOR]

A highly efficient MgBi2O6 (MBO)/TiO2 heterostructured photocatalyst for the evolution of H2 was successfully prepared using a one-step hydrothermal method. The phase structure, microstructure and optical properties of the MBO/TiO2 composites were investigated by various experimental techniques. A series of H2 production experiments were performed under visible light. The measured results indicated that the nanostructured MBO/TiO2 composite, with a stoichiometric molar ratio of MBO:TiO2 = 0.2%, displayed the best H2 production rate of 3413 μmol h−1 g−1. The excellent photocatalytic performance of the obtained composite material was due to the heterojunction formed between MBO and TiO2, which reduced the charge transfer resistance and accelerated the separation efficiency of the photogenerated electron–hole pairs. The reaction mechanism was also discussed in detail. [ABSTRACT FROM AUTHOR]

Heterostructured AgBr/Bi 2 Sn 2 O 7 photocatalysts were synthesized successfully via the ultrasonic-assisted chemical precipitation method. XRD, FT-IR, FE-SEM, TEM, XPS, UV–vis-DRS and PL spectroscopy were used to characterize the phase structure, morphology, chemical composition, oxidation state, and optical properties of AgBr/Bi 2 Sn 2 O 7 heterojunction. The photocatalytic activity of as-prepared catalysts was evaluated by the degradation of RhB under visible light irradiation. The obtained AgBr/Bi 2 Sn 2 O 7 composite with the 1:1 molar ratio exhibited significantly enhanced photocatalytic performance. Further first-principles calculations indicated that the hybridization interaction between Ag and O atoms at AgBr/Bi 2 Sn 2 O 7 interface is expected to be beneficial for enhancing the charge transfer and improving the photocatalytic activity of heterostructured composites. [ABSTRACT FROM AUTHOR]