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Enhancing the moisture resistance of Mn4+-doped fluoride phosphors is crucial for solid-state lighting (SSL) and liquid crystal display (LCD). Herein, the deteriorated K2AF6:Mn4+ (A = Ti, Si) phosphors were restored with Na2SO3 alkaline reductant, and optimal treatment conditions were systematically determined. The kinetic process for luminescence degradation and restoration, as well as the corresponding reparation mechanism were investigated in detail. These results showed that SO32− anion can reduce Mn4+ to Mn2+, rapidly remove the dark-brown layer of the degradation product, and restore the luminescence intensity of K2AF6:Mn4+ to more than 95%. Therefore, the restored K2TiF6: Mn4+ and K2SiF6: Mn4+ samples exhibit excellent moisture resistance, maintaining to be 66 and 76% of the initial intensity after immersing in deionized water for 300 min. Furthermore, fabricated white light-emitting device using the restored K2TiF6: Mn4+ phosphor also possess color rendering index of 94.2 and correlated color temperature of 3270 K. Our results provide a feasible strategy to significantly improve the moisture resistance of fluoride phosphors, demonstrating a great promise in phosphor-converted white-LED toward lighting and display field. [ABSTRACT FROM AUTHOR]

Exploring highly efficient, stable, and low-cost electrocatalysts for CO 2 reduction reaction (CRR) can not only mitigate greenhouse gas emission but also store renewable energy. Herein, CO 2 electroreduction to HCOOH on the surface of SnX 2 (X = S and Se) monolayer-supported non-noble metal atoms (Fe, Co and Ni) was systematically investigated using first-principles calculations. Our results show that Fe, Co and Ni adsorbed on the surface of SnX 2 (X = S and Se) monolayers can effectively enhance their electrocatalytic activity for CO 2 reduction to HCOOH with low limiting potentials due to the decreasing energy barrier of *OOCH. Moreover, the lower free energy of the *OOCH intermediate on the surface of TM/SnX 2 (X = S and Se) monolayers verifies that the electroreduction of CO 2 to HCOOH prefers to proceed along the path: CO 2 → *OOCH → *HCOOH → HCOOH. Interestingly, SnX 2 (X = S and Se) monolayer-supported Co and Ni atoms prefer the HCOOH product with low CRR overpotentials of 0.03/0.01 V and 0.13/0.05 V, respectively, showing remarkable catalytic performance. This work reveals an efficient strategy to enhance the electrocatalytic performance of SnX 2 (X = S and Se) monolayers for CO 2 reduction to HCOOH, which could provide a way to design and develop new CRR catalysts experimentally in future., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)