Light-matter interactions in inorganic perovskite nanolasers are investigated using single-crystalline cesium lead halide (CsPbX3, X = Cl, Br, and I) nanowires synthesized by the chemical vapor transport method. The perovskite nanowires exhibit a uniform growth direction, smooth surfaces, straight end facets, and homogeneous composition distributions. Lasing occurs in the perovskite nanowires at low thresholds (3 μJ/cm(2)) with high quality factors (Q = 1200-1400) under ambient atmospheric environments. The wavelengths of the nanowire lasers are tunable by controlling the stoichiometry of the halide, allowing the lasing of the inorganic perovskite nanowires from blue to red. The unusual spacing of the Fabry-Pérot modes suggests strong light-matter interactions in the reduced mode volume of the nanowires, while the polarization of the lasing indicates that the Fabry-Pérot modes belong to the same fundamental transverse mode. The dispersion curve of the exciton-polariton model suggests that the group refractive index of the polariton is significantly enhanced.

Development of high-performance catalysts is very crucial for the commercialization of sustainable energy conversion technologies. Searching for stable, highly active, and low-cost multifunctional catalysts has become a critical issue. In this study, we report the synthesis of IrO 2 −ZnO hybrid nanoparticles and their highly efficient electrocatalytic activities toward oxygen/hydrogen evolution reaction (OER/HER) as well as oxygen reduction reaction (ORR). For comparison, we synthesized RuO 2 −ZnO, showing a smaller catalytic activity than IrO 2 −ZnO, which provides robust evidence for the unique synergic effect of these hybrid structures. IrO 2 −ZnO and RuO 2 −ZnO exhibit excellent OER catalytic performance with Tafel slopes of 57 and 59 mV decade −1 , respectively. For HER, IrO 2 −ZnO shows a higher catalytic activity than RuO 2 −ZnO. The numbers of electrons involved in the ORR were 3.7 and 2.8, respectively, for IrO 2 −ZnO and RuO 2 −ZnO. The remarkable catalytic performance of IrO 2 −ZnO would be ascribed to the abundant oxygen vacancies and the metallic states of Ir, which ensure excellent catalytic activity and stability.