NH3 is a valuable chemical with a wide range of applications, but the conventional Haber-Bosch process for industrial-scale NH3 production is highly energy-intensive with serious greenhouse gas emission. Electrochemical reduction offers an environmentally benign and sustainable route to convert N2 to NH3 at ambient conditions, but its efficiency depends greatly on identifying earth-abundant catalysts with high activity for the N2 reduction reaction. Here, it is reported that MnO particles act as a highly active catalyst for electrocatalytic hydrogenation of N2 to NH3 with excellent selectivity. In 0.1 m Na2SO4, this catalyst achieves a high Faradaic efficiency up to 8.02% and a NH3 yield of 1.11 × 10-10 mol s-1 cm-2 at -0.39 V versus reversible hydrogen electrode, with great electrochemical and structural stability. On the basis of density functional theory calculations, MnO (200) surface has a smaller adsorption energy toward N than that of H with the *N2 → *N2H transformation being the potential-determining step in the nitrogen reduction reaction.

Shewanella oneidensis is able to carry out extracellular electron transfer (EET), although its EET efficiency is largely limited by low flavin concentrations, poor biofilm forming-ability, and weak biofilm conductivity. After identifying an important role for riboflavin (RF) in EET via in vitro experiments, the synthesis of RF is directed to 837.74 ± 11.42 µm in S. oneidensis. Molecular dynamics simulation reveals RF as a cofactor that binds strongly to the outer membrane cytochrome MtrC, which is correspondingly further overexpressed to enhance EET. Then the cell division inhibitor sulA, which dramatically enhanced the thickness and biomass of biofilm increased by 155% and 77%, respectively, is overexpressed. To reduce reaction overpotential due to biofilm thickness, a spider-web-like hybrid biofilm comprising RF, multiwalled carbon nanotubes (MWCNTs), and graphene oxide (GO) with adsorption-optimized elongated S. oneidensis, achieve a 77.83-fold increase in power (3736 mW m-2 ) relative to MR-1 and dramatically reduce the charge-transfer resistance and boosted biofilm electroactivity. This work provides an elegant paradigm to boost EET based on a synthetic biology strategy and materials science strategy, opens up further opportunities for other electrogenic bacteria.

Cu-based catalysts exhibit excellent performance in hydrogenation reactions. However, the poor stability of Cu catalysts under high temperatures has restricted their practical applications. The preparation of stable Cu catalysts supported by SiO2 with strong metal-support interaction (SMSI) has thus aroused great interest due to the high abundance, low toxicity, feasible processability, and low cost of SiO2 . The challenge in the construction of such SMSI remains to be the inertness of SiO2 . Herein, a simple and scalable method is developed to prepare 2D silica (2DSiO2 ) supported Cu catalysts with SMSI by carefully manipulating the topological exfoliation of CaSi2 with CuCl2 and thereafter calcination. The prepared Cu-2DSiO2 catalysts with the unique encapsulated Cu nanoparticles exhibit excellent activity and long-term stability in high-temperature CO2 hydrogenation reactions. This feasible and low-cost solution for stabilizing Cu catalysts might shed light on their realistic applications.

A high-density Raman photometry based on a dual-recognition strategy is created for accurately quantifying acetylcholinesterase (AchE) activity in 24 brain regions of free-moving animals with network. A series of 5-ethynyl-1,2,3,3-tetramethyl-based molecules with different conjugated structures and substitute groups are designed and synthesized for specific recognition of AchE by Raman spectroscopy. After systematically evaluating the recognition ability toward AchE, 2-(4-((4-(dimethylamino)benzoyl)oxy)styryl)-5-ethynyl-1,3,3-trimethyl-3H-indol-1-ium (ET-5) is finally optimized for AchE determination, which shows the highest selectivity, the greatest sensitivity, and the fastest response time among the investigated seven molecules. More interestingly, using the developed probe for AchE with high accuracy and sensitivity, the optimized AchE regulated by nitric oxide (NO) is discovered for promoting the neurogenesis of neural stem cells (NSCs). Benefiting from the high-density photometry, it is found that the activity and distribution of AchE varied in 24 brain regions, and the levels of AchE activity in 24 brain regions of Alzheimer's mice (AD) are lower than those of normal mice. It is the first time that a functional network of AchE in 24 brain regions is established. It is also found that the loss of AchE functional network in AD mice is restored and reconstructed by the controlled release of AchE regulated by NO.

Achieving scalable synthesis of nanoscale transition-metal carbides (TMCs), regarded as substitutes for platinum-group noble metals, remains an ongoing challenge. Herein, a 100-g scale synthesis of single-phased cobalt carbide (Co2 C) through carburization of Co-based Prussian Blue Analog (Co-PBA) is reported in CO2 /H2 atmosphere under mild conditions (230 °C, ambient pressure). Textural property investigations indicate a successful preparation of orthorhombic-phased Co2 C nanomaterials with Pt-group-like electronic properties. As a demonstration, Co2 C achieves landmark photo-assisted thermal catalytic CO2 conversion rates with photo-switched product selectivity, which far exceeds the representative Pt-group-metal-based catalysts. This impressive result is attributed to the excellent activation of reactants, colorific light absorption, and photo-to-thermal conversion capacities. In addition to CO2 hydrogenation, the versatile Co2 C materials show huge prospects in antibacterial therapy, interfacial water evaporation, electrochemical hydrogen evolution reaction, and battery technologies. This study paves the way toward unlocking the potential of multi-functional Co2 C nanomaterials.

As an analogue to the vapor-liquid-solid process, the solution-liquid-solid (SLS) method offers a mild solution-phase route to colloidal 1D nanostructures with controlled sizes, compositions, and properties. However, direct growth of 1D nanostructure arrays through SLS processes remains in its infancy. Herein, this study shows that SLS processes are also suitable for the growth of nanorod arrays on the substrate. As a proof of concept, seedless growth of silica nanorod arrays on a variety of hydrophilic substrates such as pristine and oxide-modified glass, metal sheets, Si wafers, and biaxially oriented polypropylene film are demonstrated. Also, the silica nanorod arrays can be used as a new platform for the fabrication of catalysts for photothermal CO2 hydrogenation and the reduction of 4-nitrophenol reactions. This work offers some fundamental insight into the SLS growth process and opens a new avenue for the mild preparation of functional 1D nanostructure arrays for various applications.