In this work, we investigate the controlled fabrication of Sn-doped TiO₂ nanorods (Sn/TiO₂ NRs) for photoelectrochemical water splitting. Sn is incorporated into the rutile TiO₂ nanorods with Sn/Ti molar ratios ranging from 0% to 3% by a simple solvothermal synthesis method. The obtained Sn/TiO₂ NRs are single crystalline with a rutile structure. The concentration of Sn in the final nanorods can be well controlled by adjusting the molar ratio of the precursors. Photoelectrochemical experiments are conducted to explore the photocatalytic activity of Sn/TiO₂ NRs with different doping levels. Under the illumination of solar simulator with the light intensity of 100 mW/cm², our measurements reveal that the photocurrent increases with increasing doping level and reaches the maximum value of 1.01 mA/cm² at −0.4 V versus Ag/AgCl, which corresponds to up to about 50% enhancement compared with the pristine TiO₂ NRs. The Mott-Schottky plots indicate that incorporation of Sn into TiO₂ nanorod can significantly increase the charge carrier density, leading to enhanced conductivity of the nanorod. Furthermore, we demonstrate that Sn/TiO₂ NRs can be a promising candidate for photoanode in photoelectrochemical water splitting because of their excellent chemical stability.

Organic–inorganic halide perovskite materials exhibit excellent memristive properties, such as high ON/OFF ratio and low switching voltage. However, the toxicity of lead and poor stability strictly limit their further commercial applications. Herein, a high-quality nontoxic and stable AgBiI₄ perovskite film is successfully synthesized via a low-temperature dynamic hot casting method, and resistive switching (RS) memory devices based on AgBiI₄ are reported for the first time. The RS memory devices with the ITO substrate exhibit typical bipolar nonvolatile memory behaviors with an ultralow operating voltage (≈0.16 V), high ON/OFF ratio (≈10⁴), reversible RS by pulse voltage operation (>700) and long data retention (>10⁴ s), superior to those of most of the other perovskite-based memory devices. Furthermore, a high performance flexible nonvolatile resistive switching (RS) memory device based on a AgBiI₄ perovskite with a PEN substrate is fabricated. The flexible device also displays good stability under repeated bending tests (>1000 cycles). By analyzing the current–voltage responses, and the transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy results, we propose a mechanism involving conducting filaments formed by Ag cations to describe the RS behavior of the Ag/PMMA/AgBiI₄/ITO device. Our work demonstrates that AgBiI₄ is promising for nonvolatile memory devices and paves the way for realizing low-power consumption flexible nonvolatile memory devices.