This work demonstrates the molecular engineering of active sites on a graphene scaffold. It was found that the N-doped graphene nanosheets prepared by a hightemperature nitridation procedure represent a novel chemical function of efficiently catalyzing aerobic alcohol oxidation. Among three types of nitrogen species doped into the graphene latticepyridinic N, pyrrolic N, and graphitic N the graphitic sp 2 N species were established to be catalytically active centers for the aerobic oxidation reaction based on good linear correlation with the activity results. Kinetic analysis showed that the N-doped graphene-catalyzed aerobic alcohol oxidation proceeds via a Langmuir−Hinshelwood pathway and has moderate activation energy (56.1 ± 3.5 kJ•mol −1 for the benzyl alcohol oxidation) close to that (51.4 kJ•mol −1 ) proceeding on the catalyst Ru/Al 2 O 3 reported in literature. An adduct mechanism was proposed to be different remarkably from that occurring on the noble metal catalyst. The possible formation of a sp 2 N−O 2 adduct transition state, which can oxidize alcohols directly to aldehydes without any byproduct, including H 2 O 2 and carboxylic acids, may be a key element step. Our results advance graphene chemistry and open a window to study the graphitic sp 2 nitrogen catalysis.

Two important and unsolved problems in the food industry and also fundamental questions in colloid chemistry are how to measure molecular distributions, especially antioxidants (AOs), and how to model chemical reactivity, including AO efficiency in opaque emulsions. The key to understanding reactivity in organized surfactant media is that reaction mechanisms are consistent with a discrete structures-separate continuous regions duality. Aggregate structures in emulsions are determined by highly cooperative but weak organizing forces that allow reactants to diffuse at rates approaching their diffusion-controlled limit. Reactant distributions for slow thermal bimolecular reactions are in dynamic equilibrium, and their distributions are proportional to their relative solubilities in the oil, interfacial, and aqueous regions. Our chemical kinetic method is grounded in thermodynamics and combines a pseudophase model with methods for monitoring the reactions of AOs with a hydrophobic arenediazonium ion probe in opaque emulsions. We introduce (a) the logic and basic assumptions of the pseudophase model used to define the distributions of AOs among the oil, interfacial, and aqueous regions in microemulsions and emulsions and (b) the dye derivatization and linear sweep voltammetry methods for monitoring the rates of reaction in opaque emulsions. Our results show that this approach provides a unique, versatile, and robust method for obtaining quantitative estimates of AO partition coefficients or partition constants and distributions and interfacial rate constants in emulsions. The examples provided illustrate the effects of various emulsion properties on AO distributions such as oil hydrophobicity, emulsifier structure and HLB, temperature, droplet size, surfactant charge, and acidity on reactant distributions. Finally, we show that the chemical kinetic method provides a natural explanation for the cut-off effect, a maximum followed by a sharp reduction in AO efficiency with increasing alkyl chain length of a particular AO. We conclude with perspectives and prospects.

Via edge engineering, a facile two‐step method is demonstrated that produces solid edge‐on junctions between TiO2 and few‐layered MoS2 in large scale. MoS2/TiO2 edge‐on heterostructures result in high conductive MoS2/TiO2 interfaces and optimized electron transport pathways that facilitate the electron–hole pair separation, leading to an efficient solar water splitting.

A 64-fold improved efficiency of solar-to-hydrogen conversion (SHC) was achieved via exposing Au nanoparticles (NPs) on the {001} facets of anatase TiO 2 nanosheets. The SHC follows a surface plasmon resonance-mediated electron injection mechanism, where Au NPs can not only harvest visible light and convert them to free energetic electrons, but promote the SHC by increasing the electron-hole pair formation rate driven by the electromagnetic field formed nearby the semiconductor.