In this work, the perovskite solar cells (PSCs) were fabricated with the bandgap-tunable (FA)x(MA)1-xPbI3 absorber layers through a facile two-stage deposition route. The doping was realized by adding the formamidinium iodide (FAI) into a precursor MAI solution. Both the surface morphology and electrochemical impedance spectra (EIS) were con-ducted to evaluate the absorber layers or solar cells. After the optimization, the best PSC performance of 14.73% was achieved at a nominal FAI content of 12.5 at.%. The performance enhancement was attributed to both the enhance-ment of visible light harvesting and carrier transport capability. Besides, the stability of a PSC device based on the single MAPbI3 absorber layer was also investigated, and a power conversion efficiency (PCE) of 11.27 % remained even after laying in vacuum for 10 days.

Ag3PO4 microparticles (MPs) were prepared through a facile chemical precipitation route and using silver acetate (AgAc) as metal salt. The effect of annealing temperature (Ta) and time (τa) on the actual photocatalytic (PC) activity of Ag3PO4 MPs is investigated. The optimal annealing parameters are Ta of 400 °C and τa of 90 min. The enhanced PC activity by annealing at 400 °C is ascribed to the increase of electron mobility. Besides, an Ag3PO4 photoelectrode was fabricated through a drop-coating deposition route, which demonstrates a photocurrent density of 80 μA/cm2 and ac-ceptable stability. The n-type conduction behavior of Ag3PO4 is verified by a Mott-Schottky (M-S) plot.

TiO₂nanorod arrays (NRAs) were prepared on fluorine doped tin oxide (FTO) substrates by a facile two-step hydrothermal method. The nanorods were selectively grown on the FTO regions which were covered with TiO₂seeding layer. It took 5 h to obtain the compact arrays with the nanorod length of ~2 μm and diameter of ~50 nm. The photoelectrochemical (PEC) properties of TiO₂NRAs are also investigated. It is demonstrated that the TiO₂NRAs indicate the good photoelectric conversion ability with an efficiency of 0.22% at a full-wavelength irradiation. A photocurrent density of 0.21 mA/cm²is observed at 0.7 V versus the saturated calomel electrode (SCE). More evidences suggest that the charge transferring resistance is lowered at an irradiation, while the flat-band potential (Vfb) is shifted towards the positive side.

TiO₂nanorod arrays (NRAs) were synthesized directly on the fluorine tin oxide (FTO) coated glass substrates by a facile hydrothermal route. The effects of growth time on the photoelectrochemical (PEC) properties of TiO₂NRAs are investigated. The samples synthesized for 4 h exhibit a photocurrent intensity of 0.37 mA/cm²at the irradiation of Xe lamp and a bias of 0 V. As the growth time increases, the thickness and order degree of the NRAs are enhanced, but the photocurrent is reduced a lot. It might be associated with the hindering of a high background electron density in NRs due to the long-time hydrothermal reaction in acid environment. Moreover, the decline behavior is observed, which is attributed to the poor charge separation capacity of TiO₂array electrodes and could be suppressed efficiently by applying a suitable positive bias.

Ag₃PO₄/AgCl hybrids have been synthesized via a facile ion-exchange method. The hybrids exhibit an enhanced photocatalytic activity for degradation of rhodamine B (RhB) than the single Ag₃PO₄or AgCl under a visible light irradiation. Such a behavior might be attributed to the increased number of high active sites and suitable energy band structure. The possible mechanism is also discussed.