Carbon-based MAPbI 3 perovskite solar cells (C-PSCs) have attracted significant attention due to their low cost and stable performance. However, due to inherent structural defects and an energy level mismatch between the perovskite layer and the carbon electrode, C-PSCs still show a poorer power conversion efficiency (PCE) than traditional perovskite solar cells (PSCs). In this study, LaFeO 3 @C nanocomposite particles were successfully synthesized via pyrolysis of La-containing MIL-100(Fe) MOF gel. By introducing these pre-synthesized LaFeO 3 @C bimetallic composite oxide nanoparticles into the carbon electrode, the device featuring a FTO/SnO 2 /CH 3 NH 3 PbI 3 /LaFeO 3 @C/C architecture achieved an impressive maximum PCE of 16.35%, surpassing that of the pristine device by 9.36%. The enhanced optoelectronic performance can be primarily attributed to enhanced interfacial contacts, superior interfacial charge extraction ability, and better electrical conductivity . The LaFeO 3 @C-based device maintained more than 90% of the initial PCE after being stored for 31 days at room temperature and ambient humidity. This study provides a novel strategy for the preparation of efficient and stable C-PSCs from the perspective of spatial structure regulation of bimetallic MOF-based composites.
Jinxin Li,Dan Zhong,Feiyu Li,Kefei Li,Wencheng Ma,Jun Ma,Jingna Zhang,Aoshuang Sun
A bifunctional electro-Fenton (EF) cathode with Fe 3 O 4 -LaFeO 3 /C embedded graphite felt (GF) was synthesized through a hydrothermal process, which was used for in situ electrochemical formation of active oxygen species (ROS) for coal pyrolysis wastewater (CPW) removal. Experimental results illustrated that the mineralization efficiency of dimethylphenol (DMP) was achieved at 90.7 % within 150 min reaction. On the basis of quenching test and free radical detection, the ∙OH and ∙O 2 − were the detectable ROS in the hetero-EF system for DMP removal. Meanwhile, the formed oxygen vacancies (OVs) and the redox of Fe 2+ /Fe 3+ promoted the oxygen adsorption and H 2 O 2 activation. Density functional theory (DFT) calculations further discussed that the Fe 3 O 4 -LaFeO 3 interface possessed more downward spin density of states in the conduction band, resulting in a higher total density of states (DOS) value near the Fermi level. Moreover, the Fe 3 O 4 -LaFeO 3 /C/GF cathode displayed good recyclability with low metal ion dissolution for 5 times (99.5 % DMP removal and 78.6 % TOC removal) and underlying actual CPW application potential (80.2 % of COD removal and 100 % of total phenol (Tph) removal). Overall, this work invented a novel and stable bifunctional cathode for the efficient removal of refractory CPW in the hetero-EF system.