A facile “dots-in-zeolites” strategy is developed to synthesize a new class of CD-based TADF materials with ultralong lifetimes.

The development of wide-spectrum responsive photocatalysts for efficient formaldehyde (HCHO) removal is highly desired yet remains a great challenge. Here we successfully converted zeolitic imidazolate framework-8 (ZIF-8), one of the most well-studied metal–organic frameworks (MOFs), from routine ultraviolet-driven to novel broad-spectrum-driven photocatalyst via a facile thermal treatment. The isocyanate groups (–NCO) formed in the thermally treated ZIF-8 (ZIF-8-T) is crucial in enabling the superior photocatalytic performance in formaldehyde degradation. Specifically, the best-performing ZIF-8-T sample showed around 2.1 and 9.4 times the HCHO adsorption amount and the solar photocatalytic degradation rate, respectively, of pristine ZIF-8. In addition, ZIF-8-T exhibited visible light (λ ≥ 400 nm) photocatalytic HCHO degradation performance, photo-converting 72% and nearly 100% of 20 ppm and 10 ppm HCHO within 1 hour, respectively. This work affords new insights and knowledge that inspire and inform the design and development of MOF-based photocatalysts with broad-spectrum responses for efficient air purification operations.

Carbon dots (CDs) with red-emitting room-temperature phosphorescence (RTP) are rarely reported because of the increasing nonradiative decay of the excited states and the decreasing energy gap between the excited states and ground states. Herein, we demonstrate a facile strategy for modulating the RTP properties of CDs in terms of donor–acceptor energy transfer (EnT) in the CDs-in-zeolite system. Upon tuning of the heteroatoms (Zn²⁺, Mn²⁺) doped in the aluminophosphate zeolite frameworks, CDs@zeolite composites with green and red phosphorescence have been prepared via in situ hydrothermal synthesis. In such composites, the zeolite matrix provides an efficient confinement role in stabilizing the triplet states of CDs. Significantly, the Mn-doped zeolite could act as an energy acceptor allowing EnT from excitons of CDs to the dopant in the host matrix, generating the intriguing red RTP behavior. This work provides an effective strategy for developing CD-based composite materials with special RTP emissions as well as new fields for applications.

A new multifunctional Eu-MOF based on a cationic viologen ligand has been synthesized. It exhibits interesting photochromism, hydrochromism and sensing ability for detection of toxic Cr ₂ O ₇ ²⁻ and CrO ₄ ²⁻ anions.

X-ray-induced photochromic materials are promising candidates for X-ray detection. An effective strategy to synthesize photochromic materials is the incorporation of photochromic methylviologen (MV) into inorganic open frameworks. It is of great interest to adjust the photochromic behaviour of MV-based materials using designed synthesis of novel anionic open frameworks. A new multifunctional photo-sensitive material, MV-templated layered bimetal phosphate JU99, is presented. It possesses unique X-ray-induced photochromism at room temperature, as well as interesting photoluminescence and photovoltaic activity, all of which are reversible in response to X-ray irradiation. These properties make JU99 an excellent material for X-ray detection.