Perovskite solar cells-TiO2 tandem assembly for photoelectrocatalytic degradation of organic pollutants

Abstract In this study, a self-powered photoelectrocatalytic (PEC) device was designed using multi-walled carbon nanotubes (CNTs) and methylamine (CH 3 NH 2 ) modified perovskite solar cells (PSCs) as the power source and CNT/TiO 2 as the photoanodes. In the PSCs, CNTs and CH 3 NH 2 were used to modify the interface between the perovskite and carbon electrode to improve the photoelectronic performance. In particular, CH 3 NH 2 induced surface-healing of the CH 3 NH 3 PbI 3 perovskite thin films and the CNTs acted as a charge transport pathway among individual perovskite nanoparticles to facilitate the collection of photogenerated holes by the carbon electrode. A power conversion efficiency of 10.39% was achieved after modification with the CNTs and CH 3 NH 2 . In the photoanodes, the CNT-modified TiO 2 electrode accelerated the electron–hole separation and transportation, thereby improving the degradation performance. After assembling the PSCs modified using CNT and CH 3 NH 2 with CNT/TiO 2 , the solar-driven PEC system exhibited a high PEC degradation rate with rhodamine B (RhB). The optimal degradation efficiency for RhB with the tandem device was close to 100% after 80 min. This low-cost tandem assembly has promising applications in pollutant degradation research.