Lead halide perovskite nanocrystals are extremely promising for photoelectronic application. However, maximizing their stability toward water, UV irradiation, or heat is yet a great challenge for the commercialization process. Herein, we develop a novel and facile surface functionalization approach that combined coating by the SiO 2 layer with surface modification by intrinsically hydrophobic methyl groups for the fabrication of superhydrophobic SiO 2 -coated CsPbBr 3 (referred as SH-CsPbBr 3 @SiO 2 ) nanoparticle films. The SiO 2 coating is realized by the hydrolysis of tetramethyl orthosilicate in the presence of ammonia. Hexamethyldisilazane is introduced for nanoparticle surface modification and thus offers the nanoparticle films' superhydrophobic performances. By optimizing the surface coating and modification, the static water contact angle and sliding angle on the representative SH-CsPbBr 3 @SiO 2 core−shell nanoparticle film can reach 160 and 3°, respectively. As a synergetic contribution from SiO 2 coating and modification by methyl groups, the as-fabricated green-emissive SH-CsPbBr 3 @SiO 2 films exhibit excellent water repellency, self-cleaning, and ultrahigh stability toward water, heat, and UV illumination. It is of great interest that the photoluminescence (PL) intensity of the SH-CsPbBr 3 @SiO 2 sample increases by 46% after 180 days under ambient conditions due to the phase transformation from CsPbBr 3 to CsPb 2 Br 5 and Pb(OH)Br. The resulting CsPb 2 Br 5 -based luminescent film shows excellent aqueous stability with remaining 75% of its initial PL intensity after soaking in water for 10 days. The white-light-emitting diode device fabricated using the green-emissive nanoparticles reports more than 20% external quantum efficiency (EQE), and no noticeable decrease in EQE is observed even after 2 weeks. This work elucidates a facile surface engineering strategy to prepare luminescent films with ultrahigh stability.

Graphical Table of ContentsAn anti-flashover material was developed by fabricating a robust superamphiphobic coating with unique gradient and micro-nanoscale hierarchical textures.

Doping Mn2+ ions into lead halide perovskite (LHP) nanocrystals (NCs) has attracted great attention in the optoelectronic fields due to the stability enhancement and unique dual-color emission characteristics arising from...

Halide perovskite nanomaterials have demonstrated promising potential in various fields, including photocatalysis for environmental remediation. However, perovskites' poor stability toward water makes it difficult to use them for the photocatalytic degradation of organic pollutants in wastewater. Herein, we develop a facile and scalable NaBr-assisted room-temperature aqueous phase procedure for the synthesis of all-inorganic CsPbBr 3 -embedded PbBr(OH) with controlled hierarchical structures, excellent ambient stability, and strong activity for photocatalytic degradation of dyes (e.g., methyl orange and methylene blue) in simulated organic wastewater. It is exceptional that the added NaBr can complex PbBr 2 to form a transparent aqueous solution, enabling the subsequent reaction with the aqueous Cs 2 CO 3 precursor to produce CsPbBr 3 -embedded PbBr(OH) microflowers and microspheres. The photocatalysis shows that the CsPbBr 3 -embedded PbBr(OH) photocatalysts exhibit excellent photocatalytic activity for dye degradation under visible-light irradiation, which is significantly stronger than that of commercial TiO 2 and some other perovskite-based materials produced using a previously reported method. The excellent stability of the CsPbBr 3 -embedded PbBr(OH) as a photocatalyst is verified by nine consecutive photocatalytic cycles without a noticeable drop in photodegradation efficiency. This work will shed light on the green synthesis of ultra-stable perovskite-based nanomaterials for photocatalytic degradation of organic pollutants as well as other promising water treatment technology prospects.

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