Halide perovskite quantum dots (QDs), primarily regarded as optoelectronic materials for LED and photovoltaic devices, have not been applied for photochemical conversion (e.g., water splitting or CO reduction) applications because of their insufficient stability in the presence of moisture or polar solvents. Herein, we report the use of CsPbBr QDs as novel photocatalysts to convert CO into solar fuels in nonaqueous media. Under AM 1.5G simulated illumination, the CsPbBr QDs steadily generated and injected electrons into CO, catalyzing CO reduction at a rate of 23.7 μmol/g h with a selectivity over 99.3%. Additionally, through the construction of a CsPbBr QD/graphene oxide (CsPbBr QD/GO) composite, the rate of electron consumption increased 25.5% because of improved electron extraction and transport. This study is anticipated to provide new opportunities to utilize halide perovskite QD materials in photocatalytic applications.

In this report, a novel zero-dimensional CsPbBr 3 nanocrystal (CsPbBr 3 NC)/two-dimensional Pd nanosheet (Pd NS) composite photocatalyst is prepared to afford efficient and stable photocatalytic gaseous CO 2 reduction in the presence of H 2 O vapor under visible light illumination. Pd NS herein acts as an electron reservoir to quickly separate the electron−hole pairs in CsPbBr 3 NC through a Schottky contact, and provides an ideal site for CO 2 reduction reactions. A highest electron consumption rate of 33.79 μmol g −1 h −1 is achieved by the CsPbBr 3 NC/Pd NS composite, which corresponds to a 2.43-fold enhancement over pristine CsPbBr 3 NC (9.86 μmol g −1 h −1 ), thus providing a practical and universal solution for the halide perovskite materials to boost the photocatalytic performance through semiconductor/metal design.

CsPbBr3I3−x/CNT hybrid thin-film photoelectrodes are fabricated and offer great potential in photoelectrochemical applications.

Direct detection of fluoxetine and its metabolite norfluoxetine in living fish brains was realized for the first time by using a novel solid-phase microextraction fiber, which was prepared by mixing the polyelectrolyte in the oligomer of silicone rubber and followed by in-mold heat-curing. The polyelectrolyte was finally encased in microcapsules dispersed in the cured silicone rubber. The fiber exhibited excellent interfiber reproducibility (5.4-7.1%, n = 6), intrafiber reproducibility (3.7-4.6%, n = 6), and matrix effect-resistant capacity. Due to the capacity of simultaneously extracting the neutral and the protonated species of the analytes at physiological pH, the fiber exhibited high extraction efficiencies to fluoxetine and norfluoxetine. Besides, the effect of the salinity on the extraction performance and the competitive sorption between the analytes were also evaluated. Based on the small-sized custom-made fiber, the concentrations of fluoxetine and norfluoxetine in the brains of living fish, which were exposed to waterborne fluoxetine at an environmentally relevant concentration, were determined and found 4.4 to 9.2 and 5.0 to 9.2 times those in the dorsal-epaxial muscle. The fiber can be used to detect various protonated bioactive compounds in living animal tissues.