The electrochemical CO2 reduction reaction (CO2RR) represents a very promising future strategy for synthesizing carbon-containing chemicals in a more sustainable way. In spite of great progress in electrocatalyst design over the last decade, the critical role of wettability-controlled interfacial structures for CO2RR remains largely unexplored. Here, we systematically modify the structure of gas-liquid-solid interfaces over a typical Au/C gas diffusion electrode through wettability modification to reveal its contribution to interfacial CO2 transportation and electroreduction. Based on confocal laser scanning microscopy measurements, the Cassie-Wenzel coexistence state is demonstrated to be the ideal three phase structure for continuous CO2 supply from gas phase to Au active sites at high current densities. The pivotal role of interfacial structure for the stabilization of the interfacial CO2 concentration during CO2RR is quantitatively analysed through a newly-developed in-situ fluorescence electrochemical spectroscopic method, pinpointing the necessary CO2 mass transfer conditions for CO2RR operation at high current densities.

of OER, a complex four-electron redox process involving OO bond formation that typically requires a high overpotential. [2] RuO 2 and IrO 2 are currently the stateof-the-art materials for OER, though the high cost and low earth abundance of Ru and Ir motivates the search for low-cost alternatives. Layered double hydroxides (LDHs), due to flexible chemical composition, show great potential in photo/ electrocatalysis. [3] Since the first report of NiFe-LDH-based materials exhibiting high OER activity, [4] much research effort has been directed toward the optimization of the OER activity of LDH materials. Hu and co-worker reported that monolayer NiM-LDH nanosheets (M = Fe, Co, etc.) exhibit efficient performance for water oxidation at low overpotentials (0.3 V at 10 mA m −2 ). [5] CoMn, [6] NiCo, [7] NiCoFe, [8] NiV, [9] and VFebased ultrathin LDH nanosheets also show good performance in OER, and core-shell Cu nanowires@NiFe-LDH nanosheets give excellent overall water splitting activity, [10] all the above mainly due to the high surface area and abundance of active surface sites. [11] However, the LDH nanosheet catalysts reported to date generally possess lateral platelet dimensions greater than 30 nm (Table S1, Supporting Information). These platelets are too large to dramatically improve the catalytic performance due to the limited availability of edge and corner sites that are typically highly reactive sites due to coordinative unsaturation. [12] Ultrafine monolayer LDHs with the lateral size of less than 3 nm containing highly exposed coordinatively unsaturated edge or corner active sites are thus a prized research target, potentially offering large catalytic performance improvements compared to conventional monolayer LDH nanosheets. However, the direct synthesis of ultrafine monolayer LDHs has proved extremely challenging to date, thus the potential of ultrafine monolayer LDHs to enhance catalytic and electrocatalytic applications remains unexplored.Traditionally, LDH nanosheets are synthesized with a lateral size of 30-200 nm and monolayer thicknesses using topdown (including solvent exfoliation [13] and plasma etching [14] ) or bottom-up approaches [5,15] (microemulsion methods [16] and layer growth inhibitors [15c,17] ). Reducing the lateral size further to sub-3 nm is challenging due to rapid crystallization kinetics and/or platelet aggregation. [18] Recently, 7.8 nm LDH nanoclusters containing only several layers were obtained using propylene oxide and acetylacetone as solvents, [19] and some ≈5 nm LDH nanosheets have been reported when LDHs were grown in situ on graphene-based supports. [20] Such approaches This study reports the synthesis of ultrafine NiFe-layered double hydroxide (NiFe-LDH) nanosheets, possessing a size range between 1.5 and 3.0 nm with a thickness of 0.6 nm. Abundant metal and oxygen vacancies impart the ultrafine nanosheets with semi-metallic character, and thus superior charge transfer properties and electrochemical water oxidation performance with overpotentials (η) of 254 mV r...

Mouse models are widely used for studying gastrointestinal (GI) tract-related diseases. It is necessary and important to develop a new set of primers to monitor the mouse gut microbiota. In this study, 16S rRNA gene-targeted group-specific primers for Firmicutes, Actinobacteria, Bacteroidetes, Deferribacteres, "Candidatus Saccharibacteria," Verrucomicrobia, Tenericutes, and Proteobacteria were designed and validated for quantification of the predominant bacterial species in mouse feces by real-time PCR. After confirmation of their accuracy and specificity by high-throughput sequencing technologies, these primers were applied to quantify the changes in the fecal samples from a trinitrobenzene sulfonic acid-induced colitis mouse model. Our results showed that this approach efficiently predicted the occurrence of colitis, such as spontaneous chronic inflammatory bowel disease in transgenic mice. The set of primers developed in this study provides a simple and affordable method to monitor changes in the intestinal microbiota at the phylum level.

Ammonia and its derived products are vital to modern societies. Artificial nitrogen fixation to ammonia via the Haber–Bosch process has been employed industrially for over 100 years. However, the Haber–Bosch process is energy intensive and not sustainable in its current form as it uses hydrogen sourced from steam methane reforming to reduce N2. The roadmap to sustainable NH3 production demands the discovery of novel approaches for nitrogen fixation under near ambient conditions that preferably use water as the reducing agent. Over the last decade, great efforts have been made to develop catalysts capable of N2 fixation under mild reaction conditions, using strategies such as low temperature thermal catalysis, nonthermal plasma catalysis, enzymatic catalysis, photocatalysis, and electrocatalysis to generate ammonia and other valuable nitrogen‐containing chemicals. In parallel with catalytic performance studies, researchers have also placed emphasis on the mechanistic understanding of natural and artificial nitrogen fixation catalysts. In this work, the various routes now being explored for nitrogen fixation are summarized. The different dinitrogen activation and hydrogenation pathways are described, whilst describing key advances made to date on the journey toward near ambient ammonia synthesis. Key obstacles that need to be overcome to attract industry interest are also discussed.

Photocatalysis as one of the future environment technologies has been investigated for decades.D espite great efforts in catalyst engineering,t he widely used powder dispersion and photoelectrode systems are still restricted by sluggish interfacial mass transfer and chemical processes.Here we develop ascalable bilayer paper from commercialized TiO 2 and carbon nanomaterials,s elf-supported at gas-liquid-solid interfaces for photothermal-assisted triphase photocatalysis. The photogeneration of reactive oxygen species can be facilitated through fast oxygen diffusion over triphase interfaces,w hile the interfacial photothermal effect promotes the following free radical reaction for advanced oxidation of phenol. Under full spectrum irradiation, the triphase system shows 13 times higher reaction rate than diphase controlled system, achieving 88.4 %mineralization of high concentration phenol within 90 min full spectrum irradiation. The bilayer paper also exhibits high stability over 40 times cycling experiments and sunlight driven feasibility,s howing potentials for large scale photocatalytic applications by being further integrated into atriphase flowr eactor.

Dry reforming of methane (DRM) with carbon dioxide to produce syngas is currently attracting a lot of attention for converting greenhouse gases into valuable chemicals. However, harsh reaction conditions in thermal catalysis hinder practical applications. Herein, a series of alumina‐supported NixFey nanoalloys are synthesized from NiFeAl‐layered double hydroxide precursors, with the obtained catalysts used for photothermal synergistic DRM. The Ni3Fe1 nanoalloy catalyst shows a syngas production rate of 0.96 mol g–1 h–1 under a 350 °C photothermal condition, which is about 1100 times higher than that of the same catalyst at the same temperature in the dark. Methane activation as the rate‐determining step in DRM is greatly enhanced by the localized surface plasmon resonance of the Ni3Fe1 nanoalloy in the ultraviolet region, thus accounting for the remarkably reduced reaction temperature. Meanwhile, the nanoalloy‐based photothermal synergistic DRM exhibits sunlight‐driven feasibility and 20 h of continuous operational stability.

Industrial nitric acid production involves multistep processes operating at high temperatures and pressures. Photocatalysis offers an alternative approach for directly transforming nitrogen molecules into nitrogen‐containing compounds under ambient conditions but still faces visible light utilization and product selectivity restrictions. Herein, a tandem photothermal‐assisted photocatalytic nitrogen oxidation system based on palladium‐decorated hydrogenated titanium oxide is fabricated, in which nitric acid is produced as the only nitrogen fixation product. The yield of nitric acid increases from 0.56 µmol g−1 h−1 at room temperature to 4.58 µmol g−1 h−1 (1.42 ppm) at 200 °C, accompanied by an enhanced quantum yield from 0.24% to 0.99% at 350 nm. The photothermal effect of palladium nanoparticles promotes the generation of superoxide radicals and nitrogen oxide intermediates in the gas–solid phase nitrogen oxidation process and contributes to improved nitric acid productivity. Therefore, the photothermal‐assisted photocatalytic nitrogen oxidation strategy opens new avenues toward developing clean and energy‐saving nitric acid production.

A theranostic strategy based on biorthogonal cycloaddition was designed to form GNP aggregates, enabling bacterial SERS imaging and photothermal therapy.