Self-healing perovskite solar cells based on copolymer-templated TiO2 electron transport layer

Solvothermal synthesis of SnO2 nanoparticles for perovskite solar cells application

Perovskite solar cells show great potential application prospects in the field of solar cells due to their promising properties. However, most perovskite solar cells that exhibit excellent photovoltaic performance typically require a carrier transport layer that necessitates a high-temperature annealing process. This greatly restricts the scalability and compatibility of perovskite solar cells in flexible electronics. In this paper, SnO2 nanoparticles with high crystallinity, good dispersibility and uniform particle size distribution are first prepared using a solvothermal method and dispersed in n-butanol solution. SnO2 electron transport layers are then prepared by a low-temperature spin coating method, and the photovoltaic characteristics of perovskite solar cells prepared with different SnO2 nanoparticles/n-butanol concentrations are studied. Results indicate that the rigid perovskite solar cell achieves the highest power conversion efficiency of 15.61% when the concentration of SnO2 nanoparticles/n-butanol is 15 mg mL-1. Finally, our strategy is successfully applying on flexible perovskite solar cells with a highest PCE of 14.75%. Our paper offers a new possibility for large-scale preparation and application of perovskite solar cells in flexible electronics in the future.

Nanosized core-shell (NiFe2O4/TiO2) heterostructure for enhanced photodegradation against polycyclic aromatic hydrocarbons

The global level of attention has been raised for photocatalytic pollutant removal technologies for degrading organic pollutants because of rising concerns about their toxicity. In this study, NiFe2O4/TiO2 core shells and pure samples of NiFe2O4 and TiO2 were synthesized using the sol-gel process and used to degrade naphthalene which is one among the polycyclic aromatic hydrocarbons (PAHs) pollutant. The synthesized materials were evaluated using a variety of analytical techniques, and the typical NiFe2O4/TiO2 core-shell results showed good purity and a lack of other impurity structures. Through morphological characterization, the core-shell structure of NiFe2O4/TiO2 has been established. However, the activity of visible light degradation was boosted by the generation of hydroxyl radicals after the electron-hole pair was delayed. Additionally, a lower band gap in NiFe2O4/TiO2 than in pure materials promotes photocatalytic activity. Similarly, photocatalytic naphthalene elimination by the core-shell achieved 67% efficiency after 150 min of visible light exposure. Furthermore, the produced core-shell has a high magnetic property, making separation from the photo-irradiated solutions easier; as a result, recycling was likely successful up to three cycles. The photocatalytic mechanism of the NiFe2O4/TiO2 composite was proposed. This research could also be applied to the degradation of other polycyclic aromatic hydrocarbon contaminants.