All-brominated inorganic perovskite CsPbBr 3 has received much attention in the field of optoelectronic applications owing to its superb stability and ease of manufacture under the ambient condition. However, the tedious process and toxic solvent are two major challenges for fabrication of CsPbBr 3 films via a multi-step deposition method . Here, we demonstrate a sustainable bi-solvent system for preparing high-quality CsPbBr 3 films in a triple-step solution-processed route, where the bi-solvent system comprises of green solvent water and ethylene glycol monomethyl ether (EGME) in place of the noxious methanol for CsBr solution. By adjusting the temperature of heat treatment and spin-coating speed, the pinhole-free, ultra-smooth and high crystallinity of CsPbBr 3 films were obtained. As a result, the CsPbBr 3 PSC prepared from the green bi-solvent system demonstrates an optimal power conversion efficiency (PCE) of 9.55%, which is one of the highest efficiencies for planar carbon-based PSCs without hole transport layer. Moreover, the all-inorganic unpacked PSCs exhibit excellent humidity stability under ambient environment for 34 days. Our result not only offers a facile and simple way to fabricate the pure-phase CsPbBr 3 films, but also alleviates the solvent toxicity during the preparation of CsPbBr 3 PSCs.
Single-crystalline ordered macro–microporous CuBTC (SOM–CuBTC) is a promising carrier for lipase immobilization due to enhanced mass transfer and stability toward fatty acids. However, the low yield per mass of the template during the preparation process and the water instability of the SOM–CuBTC carrier have posed significant limitations on its practical applications. In this study, we addressed these challenges by introducing a novel dual-solvent system consisting of dimethyl sulfoxide (DMSO) and ethanol to obtain a stable precursor solution with a concentration approximately 10 times higher than that in previous literature, yielding 21.4 mg of SOM–CuBTC per gram of the polystyrene template. However, the decomposition of SOM–CuBTC in an aqueous system of lipase immobilization was observed. We explored chemical vapor deposition and sol–gel methods for hydrophobic modification on SOM–CuBTC. SOM–CuBTC coated by hydrophobic polydimethylsiloxane (PDMS) via the sol–gel method possessed excellent chemical stability and exhibited great potential for lipase immobilization with a significant increase by 98.7% in the specific activity. The obtained immobilized lipase not only showed improved thermal stability and pH tolerance but also displayed excellent catalytic performance in the synthesis process of 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) by acidolysis. This work reveals the great potential of SOM–CuBTC and provides new insights into the rational design of metal–organic frameworks for enzyme immobilization in extensive applications.