Z-Scheme In2 S3 /NU-1000 Heterojunction for Boosting Photo-Oxidation of Sulfide into Sulfoxide under Ambient Conditions.

Photocatalytic oxidation of sulfide into sulfoxide has attracted extensive attention as an environmentally friendly strategy for chemical transformations or toxic chemicals degradation. Herein, we construct a series of In2 S3 /NU-1000 heterojunction photocatalysts, which can efficiently catalyze the oxidation of sulfides to form sulfoxides as the sole product under LED lamp (full-spectrum) illumination in air at room temperature. Especially, the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), can also be photocatalytically oxidized with In2 S3 /NU-1000 to afford nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) selectively and effectively. In contrast, individual NU-1000 and In2 S3 show very low catalytic activity on this reaction. The significantly improved photocatalytic activity is ascribed to the constructing of an efficient Z-scheme photocatalysts In2 S3 /NU-1000, which exhibits the enhancement of light harvesting, the promotion of photogenerated electron-hole separation, and the retention of high porosity of the parent MOF. Moreover, mechanism studies in photocatalytic oxidation reveal that the superoxide radical (. O2 - ) and singlet oxygen (1 O2 ) are the main oxidative species in the oxidation system. This work exploits the opportunities for the construction of porous Z-scheme photocatalysts based on the photoactive MOFs materials and inorganic semiconductors for promoting catalytic organic transformations. More importantly, it provides a route to the rational design of efficient photocatalysts for the detoxification of mustard gas.

BiOI Particles Confined into Metal-Organic Framework NU-1000 for Valid Photocatalytic Hydrogen Evolution under Visible-Light Irradiation.

Herein, a surface site engineering strategy is used to construct a porous Z-scheme heterojunction photocatalyst for photocatalytic hydrogen evolution (PHE) by integration of BiOI in a mesoporous Zr-based metal-organic framework (MOF) NU-1000. Three high-quality and highly dispersed BiOI@NU-1000 heterojunction materials are synthesized, and a set of methods is used to characterize these materials, indicating that the BiOI@NU-1000 heterojunction can retain high porosity and crystallinity of the parent NU-1000. Furthermore, the built-in electric field of the BiOI@NU-1000 composite can effectively tune the band gap, promote the separation of photoinduced charge carriers, improve photocurrent intensity, and reduce photoelectric impedance. Under visible-light irradiation, BiOI@NU-1000-2 showed the best photocatalytic performance in the field of MOF-based photocatalysts for PHE, with a hydrogen production rate of up to 610 µmol h-1 g-1. This study will open up opportunities for the construction of Z-scheme photocatalysts based on the highly porous MOF materials to inspire the development of innovative photocatalysts.

Functional Group Regulated Ni/Ti3C2Tx (Tx = F, -OH) Holding Bimolecular Activation Tunnel for Enhanced Ammonia Borane Hydrolysis.

Developing economical and efficient catalyst for hydrogen generation from ammonia borane (AB) hydrolysis is still a huge challenge. As an alternative strategy, the functional group regulation of metal nanoparticles (NPs)-based catalysts is believed to be capable of improving the catalytic activity. Herein, a series of Ni/Ti3C2Tx-Y (Tx = F, -OH; Y denotes etching time (d)) catalysts are synthesized and show remarkably enhanced catalytic activity on the hydrolysis of AB in contrast to the corresponding without regulating. The optimized Ni/Ti3C2Tx-4 with a turnover frequency (TOF) value of 161.0 min-1 exhibits the highest catalytic activity among the non-noble monometallic-based catalyst. Experimental results and theory calculations demonstrate that the excellent catalytic activity benefits from the bimolecular activation channels formed by Ni NPs and Ti3C2Tx-Y. H2O and AB molecules are activated simultaneously in the bimolecular activation tunnel. Bimolecular activation reduces the activation energy of AB hydrolysis, and hydrogen generation rate is promoted. This article provides a new approach to design effective catalysts and further supports the bimolecular activation model for the hydrolysis of AB.

Construction of porous 2D MOF nanosheets for rapid and selective adsorption of cationic dyes.

Porous two-dimensional metal-organic framework (2D-MOF) nanosheets Zr-BTB-H4TBAPy and PCN-134-2D were synthesized and characterized by X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and zeta potential and subjected to dye adsorption and separation investigation. These 2D-MOF nanosheets are ultrathin, have large surface area and high water stability and can selectively adsorb cationic dyes, rhodamine B (RhB) and methylene blue (MLB), from aqueous solutions, with removal rates of nearly 100% within 10 min. The adsorption kinetic results showed that Zr-BTB-H4TBAPy and PCN-134-2D could effectively and selectively remove cationic dyes from water, followed a pseudo-second-order kinetic model and fitted well with the Freundlich isotherm. The adsorption mechanism studies further indicated that their excellent adsorption and separation performance could be ascribed to their ultrathin and porous features, plentiful exposed surface-active sites, and favorable electrostatic interactions between the adsorbents and cationic dyes. Moreover, the porous 2D MOF nanosheets displayed excellent recyclability and reusability. These outstanding features make them potentially applicable for rapid and selective cationic dye adsorption and separation.