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Exploiting the Bragg mirror effect of photonic crystal photoelectrode is desperately desired for photoelectrochemical water splitting. Herein, a novel TiO2 nanotube photonic crystal bi-layer structure consisting of a top nanotube layer and a bottom nanotube photonic crystal layer is presented. In this architecture, the photonic bandgap of bottom TiO2 nanotube photonic crystals can be precisely adjusted by modulating the anodization parameters. When the photonic bandgap of bottom TiO2 nanotube photonic crystals overlaps with the electronic bandgap of TiO2, the bottom TiO2 nanotube photonic crystal layer will act as a Bragg mirror, leading to the boosted ultraviolet light absorption of the top TiO2 nanotube layer. Benefiting from the promoted UV light absorption, the TiO2 NT-115-NTPC yields a photocurrent density of 1.4 mA/cm2 at 0.22 V vs. Ag/AgCl with a Faradic efficiency of 100%, nearly two times higher than that of conventional TiO2 nanotube arrays. Furthermore, incident photon-to-current conversion efficiency is also promoted within ultraviolet light region. This research offers an effective strategy for improving the performance of photoelectrochemical water splitting through intensifying the light–matter interaction. [ABSTRACT FROM AUTHOR]

Recently, novel optical information writing strategies have been developed based on fluorescent change of halide perovskites generated by light induced structural transformation. However, to date, the repeatable writing and erasing of fluorescent patterns are still a major challenge. Herein, lead‐free Cs3InCl6:Sb3+ perovskite with photochromism and reversed thermochromism is developed for repeatable information writing and erasing. The original Cs3InCl6:Sb3+ perovskite synthesized by a modified hot‐injection method exhibits green photoluminescence (PL), which is caused by recombination of self‐trapped excitons. After treating with ultrasonication and heating, the green PL gradually turns to blue emission, which is related to surficial Cl vacancies that are generated or exposed due to the desorption of surfactants. Under continuous UV light irradiation, due to the photo repairing effect, the blue emission gradually vanishes, the fluorescent color recovers to green. Based on this photochromic effect, fluorescent patterns are drawn by UV exposure with mask. Moreover, the green PL color can again return to blue by heating at 100 °C. Thus, the photochromism‐induced fluorescent patterns can be simply erased based on the reversed thermochromism effect. Therefore, repeatable optical information writing and thermal erasure are demonstrated based on reversible PL change of Cs3InCl6:Sb3+. [ABSTRACT FROM AUTHOR]

The purposeful design and construction of two-dimensional (2D) semiconductor heterojunctions offers a promising avenue for achieving efficient photocatalytic activity. However, it remains a challenge to enable efficient charge migration at the interface. In this study, we successfully prepare 2D ultrathin Z-scheme heterojunctions based on LaVO4 and ZnIn2S4 (ZIS) with excellent contact interfaces and robust internal electric fields through oxygen vacancy and sulfur vacancy (SV) induction and molybdenum atom doping. Surface defects facilitate the formation of 2D heterojunctions. The optimized heterojunction exhibits outstanding photocatalytic hydrogen evolution performance (8.67 mmol g−1 h−1) with an apparent quantum efficiency (λ > 420 nm) of 30.57%. Mechanistic analysis and theoretical calculations demonstrate that the molybdenum atoms promote interfacial charge transfer and enhance the internal electric field between the LaVO4 and SV-MZIS interfaces, ultimately leading to the formation of a Z-scheme charge transfer channel. This work establishes an engineering design model for atomic-scale 2D interfaces with modulated charge transfer. [ABSTRACT FROM AUTHOR]

Double perovskite (DP) is considered as a promising candidate for single‐component white‐light emitters. However, the photoluminescence (PL) efficiency of the small sized DP, such as microcrystals and nanocrystals, is generally unsatisfactory. In this work, by comparing the Sb/Bi co‐doped Cs2NaInCl6 microcrystals prepared at different conditions, it is revealed that the PL spectral profile and efficiency are highly dependent on intrinsic strain effect. All the Sb/Bi co‐doped Cs2NaInCl6 DPs exhibit blue PL at ≈445 nm and yellow PL at ≈560 nm. When the crystal size decreases, the release of local strain results in a significant quenching in the emission intensity. Accordingly, by optimizing the reaction conditions to introduce sufficient lattice mismatch, high PL quantum yields (QYs) of 76.38% and 86.44% are obtained for blue and yellow PL, respectively. Moreover, a white light‐emitting convertor with a high colour rendering index (CRI) of 90.0 is fabricated, which shows a luminous efficiency of 40.4 lm W−1. [ABSTRACT FROM AUTHOR]

In a dual-chamber photocatalytic fuel cell device, polyvinyl alcohol degradation and H2 evolution were concurrently achieved. The setup involved commercial P25 as the photoanode and Ag@Fe2O3 nanoparticles as the cathode. Additionally, the feasibility of a Fenton-like reaction in the cathode, utilizing Fe2+ ions and pumped O2, was demonstrated. Different cathode materials, polyvinyl alcohol types, and pH values' effects were assessed on device performance. Quenching tests highlighted photoinduced holes (h+) and OH· radicals as pivotal contributions to polyvinyl alcohol degradation. Long-term stability of the device was established through cycling experiments. [ABSTRACT FROM AUTHOR]

The combination of SiC quantum dots sensitized inverse opal TiO2 photocatalyst is designed in this work and then applied in wastewater purification under simulated sunlight. From various spectroscopic techniques, it is found that electrons transfer directionally from SiC quantum dots to inverse opal TiO2, and the energy difference between their conduction/valence bands can reduce the recombination rate of photogenerated carriers and provide a pathway with low interfacial resistance for charge transfer inside the composite. As a result, a typical type-II mechanism is proved to dominate the photoinduced charge transfer process. Meanwhile, the composite achieves excellent photocatalytic performances (the highest apparent kinetic constant of 0.037 min−1), which is 6.2 times (0.006 min−1) and 2.1 times (0.018 min−1) of the bare inverse opal TiO2 and commercial P25 photocatalysts. Therefore, the stability and non-toxicity of SiC quantum dots sensitized inverse opal TiO2 composite enables it with great potential in practical photocatalytic applications. [ABSTRACT FROM AUTHOR]