The exploration of inexpensive, facile, and large‐scale methods to prepare carbon scaffolds for high sulfur loadings is crucial for the advancement of Li–S batteries (LSBs). Herein, the authors report a new nitrogen and oxygen in situ dual‐doped nonporous carbonaceous material (NONPCM) that is composed of a myriad of graphene‐analogous particles. Importantly, NONPCM could be fabricated on a kilogram scale via inexpensive and green hydrothermal‐carbonization‐combined methods. Many active sites on the NONPCM surface are accessible for the efficient surface‐chemistry confinement of guest sulfur and its discharge product; this confinement is exclusive of physical entrapment, considering the low surface area. Electrochemical examination demonstrates excellent cycle stability and rate performance of the NONPCM (K)/S composite, even with a sulfur loading of 80 or 90 wt%. Hence, the scaffolds for LSBs exhibit potential for industrialization through further optimization and expansion of the present synthesis.

Heptazine-assembled polymeric carbon nitride (CN) materials have fascinated the research community as a photocatalyst for hydrogen evolution while less attention has been devoted to the mechanistic features of the host materials. Using excited-state nonadiabatic dynamics simulations, the molecular-level picture of the decomposition of heptazine hydrogen bonded to water molecule(s) (heptazine−water complex) into heptazinyl and hydroxyl biradical products is revealed. Dynamics simulations show that hydrogen detachment from the water molecule to the heptazine occurs within tens of femtoseconds and suggest that excited-state deactivation via N− H••••••O−H electron-driven proton transfer (EDPT) is the dominant and most relevant excited-state deactivation process in heptazine−water complexes leading to conical intersection. The observation of photorelaxation-induced water splitting by heptazine is proof of the water-splitting reaction principle, which presents further challenges for computational and experimental investigations of the deactivation of heptazinyl and OH biradical products for efficient hydrogen evolution.

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Functionalization dependence of the optical properties of graphene quantum dots.

Recent experiments have suggested that exciton self-trapping plays an important role in governing the optical properties of graphene quantum dots (GQDs) and carbon dots (CDs), while the molecular structures related to this phenomenon remain unclear. This theoretical study reports exciton self-trapping induced by edge-bonded ether (C-O-C) groups in graphene nanosheets. Density functional theory (DFT) and time-dependent DFT calculations show that the initially delocalized electron and hole are trapped in the vicinity of the edge ether groups on graphene nanosheets upon excited-state (S1) relaxation, accompanied by structural planarization of the seven-membered cyclic ether rings in the same region. The resulted significant structural deformation leads to large Stokes shift energies, which are comparable to the magnitudes of the notably large emission shift observed in experiments. This study provides a feasible explanation of the origin of exciton self-trapping and offers guidance for experiments to investigate and engineer exciton self-trapping in relevant materials.

Hydrogenated black TiO 2 is receiving everincreasing attention, primarily due to its ability to capture low-energy photons in the solar spectrum and its highly efficient redox reactivity for solar-driven water splitting. However, in-depth physical insight into the redox reactivity is still missing. In this work, we conducted a density functional theory study with Hubbard U correction (DFT+U) based on the model obtained from spectroscopic and aberration-corrected scanning transmission electron microscopy (AC-STEM) characterizations to reveal the synergy among H heteroatoms located at different surface sites where the six-coordinated Ti (Ti 6C ) atom is converted from an inert trapping site to a site for the interchange of photoexcited electrons. This indepth understanding may be applicable to the rational design of highly efficient solar-light-harvesting catalysts.

Graphitic carbon nitride (g-CN) has been widely studied as a promising candidate for water splitting, owing to its metal-free nature, moderate band gap, and low cost. However, its photocurrent density is still very low for photoelectrochemical cell applications. In this work, a crystal face tailored g-CN photoelectrode has been fabricated by a facile thermal vapor deposition method. We use the melamine formaldehyde resin as a new precursor and have successfully fabricated g-CN films. The intensity ratio between two typical peaks (100) and (001) of g-CN is very different from that in the existing literature. The water splitting photocurrent density is as high as 228.2 μA cm , which is 126.8 times higher than pure g-CN (1.8 μA cm ) at 1.23 V vs. reversible hydrogen electrodes under one sun illumination without sacrificial reagents and co-catalysts. The electrode shows the best performance, compared with the previously reported g-CN photoelectrodes.

Metal-organic frameworks (MOFs) heterostructures with domain-controlled emissive colors have shown great potential for achieving high-throughput sensing, anti-counterfeit and information security.H ere,astrategy based on sterichindrance effect is proposed to construct lateral lanthanide-MOFs (Ln-MOFs) epitaxial heterostructures,where the channel-directed guest molecules are introduced to rebalance inplane and out-of-plane growth rates of the Ln-MOFs microrods and eventually generate lateral MOF epitaxial heterostructures with controllable aspect ratios.Alibrary of lateral Ln-MOFs heterostructures are acquired through as tepwise epitaxial growth procedure,from which rational modulation of each domain with specific lanthanide doping species allows for definition of photonic barcodes in at wo-dimensional (2D) domain with remarkably enlarged encoding capacity.T he results providem olecular-level insight into the use of modulators in governing crystallite morphology for spatially assembling multifunctional heterostructures.