Black Tungsten Nitride as a Metallic Photocatalyst for Overall Water Splitting Operable at up to 765 nm

Semiconductor photocatalysts are hardly employed for overall water splitting beyond 700 nm, which is due to both thermodynamic aspects and activation barriers. Metallic materials as photocatalysts are known to overcome this limitation through interband transitions for creating electron–hole pairs; however, the application of metallic photocatalysts for overall water splitting has never been fulfilled. Black tungsten nitride is now employed as a metallic photocatalyst for overall water splitting at wavelengths of up to 765 nm. Experimental and theoretical results together confirm that metallic properties play a substantial role in exhibiting photocatalytic activity under red‐light irradiation for tungsten nitride. This work represents the first red‐light responsive photocatalyst for overall water splitting, and may open a promising venue in searching of metallic materials as efficient photocatalysts for solar energy utilization.     

Mass Production and Pore Size Control of Holey Carbon Microcages

Architectural control of porous solids, such as porous carbon cages, has received considerable attention for versatile applications because of their ability to interact with liquids and gases not only at the surface, but throughout the bulk. Herein we report a scalable, facile spray‐pyrolysis route to synthesize holey carbon microcages with mosquito‐net‐like shells. Using the surfaces of water droplets as the growth templates, styrene–butadiene rubber macromolecules are controllably cross‐linked, and size‐controllable holes on the carbon shells are generated. The as‐formed carbon microcages encapsulating Si nanoparticles exhibit enhanced lithium‐storage performances for lithium‐ion batteries. The scalable, inexpensive synthesis of porous carbon microcages with controlled porosity and the demonstration of outstanding electrochemical properties are expected to extend their uses in energy storage, molecular sieves, catalysis, adsorbents, water/air filters, and biomedical engineering.     

CsB4O6F: A Congruent‐Melting Deep‐Ultraviolet Nonlinear Optical Material by Combining Superior Functional Units

The discovery of new nonlinear optical (NLO) materials for coherent light generation in the deep‐ultraviolet (DUV, wavelength below 200 nm) region is essential for the development of laser technologies. Herein, we report a new material CsB₄O₆F (CBF), which combines the superior structural properties of two well‐known NLO materials, β‐BaB₂O₄ (BBO) and KBe₂BO₃F₂ (KBBF). CBF exhibits excellent DUV optical properties including a short cutoff edge (155 nm), a large SHG response (≈1.9×KDP), and a suitable birefringence that enables frequency doubling down to 171.6 nm. Remarkably, CBF melts congruently and shows an improved growth habit. In addition, our rational design strategy will contribute to the discovery of DUV NLO materials.     

Bridging Dealumination and Desilication for the Synthesis of Hierarchical MFI Zeolites

The rational design of zeolite‐based catalysts calls for flexible tailoring of porosity and acidity beyond micropore dimension. To date, dealumination has been applied extensively as an industrial technology for the tailoring of zeolite in micropore dimension, whereas desilication has separately shown its potentials in the creation of mesoporosities. The free coupling of dealumination with desilication will bridge the tailoring at micro/mesopore dimensions; however, such coupling has been prevailingly confirmed as an impossible mission. In this work, a consecutive dealumination–desilication process enables the introduction of uniform intracrystalline mesopores (4–6 nm) into the microporous Al‐rich zeolites. The decisive impacts of steaming step have been firstly discovered. These findings revitalize the functions of dealumination in porosity tailoring, and stimulate the pursuit of new methods for the tailoring of industrially relevant Al‐rich zeolites.     

Rapid Guest Exchange and Ultra‐Low Surface Tension Solvents Optimize Metal–Organic Framework Activation

Exploratory research into the critical steps in metal–organic framework (MOF) activation involving solvent exchange and solvent evacuation are reported. It is discovered that solvent exchange kinetics are extremely fast, and minutes rather days are appropriate for solvent exchange in many MOFs. It is also demonstrated that choice of a very low surface tension solvent is critical in successfully activating challenging MOFs. MOFs that have failed to be activated previously can achieve predicted surface areas provided that lower surface tension solvents, such as n‐hexane and perfluoropentane, are applied. The insights herein aid in the efficient activation of MOFs in both laboratory and industrial settings and provide best practices for avoiding structural collapse.     

Polynitro‐Functionalized Dipyrazolo‐1,3,5‐triazinanes: Energetic Polycyclization toward High Density and Excellent Molecular Stability

A new fused N‐heterocyclic framework, dipyrazolo‐1,3,5‐triazinane, was synthesized and the physiochemical properties of its derivatives were investigated to evaluate the integrated energetic performance. In contrast to 1,3,5‐trinitro‐1,3,5‐triazinane (RDX) featuring a distorted chair confirmation, polynitro‐functionalized dipyrazolo‐1,3,5‐triazinanes have nearly planar backbones, thereby enhancing the density and thermal stability. Among these new energetic tricyclic compounds, 5 a and 12 show favorable crystal densities of 1.937 g cm⁻³ and 1.990 g cm⁻³ at 150 K, respectively, which rank highest in triazinane‐based energetic compounds. Additionally, this synthetic approach was carried out to form seven‐membered and eight‐membered rings, giving rise to tetranitro dipyrazolo‐1,3,5‐triazepane ( 5 b ) and tetranitro dipyrazolo‐1,3,5‐triazocane ( 5 c ), respectively.     

Ultrathin Cell‐Membrane‐Mimic Phosphorylcholine Polymer Film Coating Enables Large Improvements for In Vivo Electrochemical Detection

Resisting biomolecule adsorption onto the surface of brain‐implanted microelectrodes is a key issue for in vivo monitoring of neurochemicals. Herein, we demonstrate that an ultrathin cell‐membrane‐mimic film of ethylenedioxythiophene tailored with zwitterionic phosphorylcholine (EDOT‐PC) electropolymerized onto the surface of a carbon fiber microelectrode (CFE) not only resists protein adsorption but also maintains the sensitivity and time response for in vivo monitoring of dopamine (DA). As a consequence, the as‐prepared PEDOT‐PC/CFEs could be used as a new reliable platform for tracking DA in vivo and would help understand the physiological and pathological functions of DA.