Green synthesis of metal-organic frameworks (MOFs) in water with alleviated environmental influence and reduced cost is an essential step to transfer laboratory MOFs research to industrial application. Switching from the commonly used organic solvents to pure water encounters challenges of the poor solubility of organic linkers, slow reaction kinetics, and the formation of polymorphic products. So far, a universal MOFs synthetic strategy in water system has yet to be developed. This study reports the seed-aided synthesis of eleven MOFs with diverse compositions and structures while pure water serving as solvent. The corresponding reaction temperature and time of using this new strategy were reduced compared with original synthetic approaches, while the products maintain porous structure and high crystallinity. The success of this strategy relies on the addition of parent MOFs as seeds which could promote crystallization process by skipping the time-consuming induction period and avoiding the formation of polymorphic impurities.

The illegal usage of antibiotics as veterinary drugs is an increasing threat for human health. The specific sensing of antibiotics with different toxicity levels is of high challenge, and mainly relies on expensive, time-consuming, and complex instruments. To realize specific sensing by rapid and handy optical sensors, a metal-organic framework (MOF) based dual sensor system is herein developed using two MOF materials BUT-128 and BUT-129 with high sensing selectivity and sensitivity. BUT-128 and BUT-129 exhibit the lowest limit of detection (LOD) towards chloramphenicol and furazolidone among reported MOF sensors. The corresponding dual sensor system with enriched signal readouts realized specific sensing of the strictly forbidden antibiotics (chloramphenicol and nitrofurans) from other regulated veterinary drugs including thiamphenicol, a structural analog of chloramphenicol. Besides, the strategy of this work is expected to flourish the development of optical sensors with high specificity for environment and food safety purposes.

Enhancing electrocatalytic water splitting performance by modulating the intrinsic electronic structure is of great importance. Here, porous bimetallic oxide and chalcogenide nanosheets grown on carbon paper denoted as NiCo₂X₄/CP (X = O, S, and Se) are prepared to demonstrate how the anion components affect the electronic structures and thereby disclose the correlation between their intermediates interaction and catalytic activities. The experimental characterization and theoretical calculation demonstrate that Se and S substitution can promote the ratio of Co³⁺/Co²⁺ and thereby modulate the electronic structure accompanied with the upshift of d band centers, which not only enhance the inner conductivity but also regulate the interaction between the catalyst surface and intermediates, especially for the adsorption of absorbed H and hydroperoxy intermediates towards respective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, a full alkaline electrolyzer using NiCo₂Se₄/CP and NiCo₂S₄/CP as cathode and anode delivers a low voltage of 1.51 V at 10 mA·cm^-2, which is comparable even superior to most transition metal-based electrolyzers.

Photocatalytic CO₂ reduction to convert solar energy to clean energy remains a critical challenge in exploring efficient catalysts. Herein, a hierarchical structured BiVO₄@Au@UiO-66-NH₂ with high photocatalytic activity was fabricated. The theoretical calculations revealed that the metal–organic framework (MOF) with relative higher conduction band (CB) and UiO-66-NH₂ with relative lower valence band (VB) could absorb full light spectrum, combining Au nanoparticle with suitable Fermi level into a particulate tandem heterojunction. This configuration can not only lower the activation barrier of CO₂ reduction using the rich active site of MOF, but also improve the selectivity toward CO by optimizing the reaction pathway. Notably, the experimental evaluation proved that BiVO₄@Au@UiO-66-NH₂ displays a producing rate of 232.7 μmol h⁻¹ g⁻¹ for CO and a selectivity of 97.2%. The investigation reveals that elaborately integrating multiple functional components into such a hierarchical structure enables optimizing crucial processes in photocatalytic CO₂ conversion and enhancing selectivity via synergistic catalysis.