Evolution and Reconstruction of Air-Electrode Surface Composition in Reversible Protonic Ceramic Cells: Mechanisms, Impacts on Catalytic Performance, and Optimization Strategies - A Review.

Reversible protonic ceramic cells (R-PCCs) are at the forefront of electrochemical conversion devices, capable of reversibly and efficiently converting chemical energy into electricity at intermediate temperatures (350-700 °C) with zero carbon emissions. However, slow surface catalytic reactions at the air-electrode often hinder their performance and durability. The electrode surface is not merely an extension of the bulk structure, equilibrium reconstruction can lead to significantly different crystal-plane terminations and morphologies, which are influenced by material's intrinsic properties and external reaction conditions.

Rod-Like Nanostructured Cu-Co Spinel with Rich Oxygen Vacancies for Efficient Electrocatalytic Dechlorination.

Dichloromethane (CHCl) hydrodechlorination to methane (CH) is a promising approach to remove the halogenated contaminants and generate clean energy. In this work, rod-like nanostructured CuCoO spinels with rich oxygen vacancies are designed for highly efficient electrochemical reduction dechlorination of dichloromethane. Microscopy characterizations revealed that the special rod-like nanostructure and rich oxygen vacancies can efficiently enhance surface area, electronic/ionic transport, and expose more active sites.

Effect of Cu-Doped Co-Mn Spinel for Boosting Low-Temperature NO Reduction by CO: Exploring the Structural Properties, Performance, and Mechanisms.

Cobalt-manganese spinel catalysts performed unsatisfactory activity at low-temperature and narrow reaction temperature window, which greatly limited the application in NO reduction by CO. Herein, we synthesize a series of Cu-doped CoMnO catalysts and apply to NO reduction by CO. The CuCoMnO exhibited superior catalytic performance, reaching 100% NO conversion and 80% N selectivity at 250 °C.

Cubic CuFeO Spinel with Octahedral Fe Active Sites for Electrochemical Dechlorination of 1,2-Dichloroethane.

CuFeO spinel has been considered as a promising catalyst for the electrochemical reaction, while the nature of the crystal phase on its intrinsic activity and the kind of active site need to be further explored. Herein, the crystal phase-dependent catalytic behavior and the main active sites of CuFeO spinel for electrochemical dechlorination of 1,2-dichloroethane are carefully studied based on the combination of experiments and theoretical calculations. Cubic and tetragonal CuFeO are successfully prepared by a facile sol-gel method combined with high temperature calcination.

Rational Design of Carbon-Based Porous Aerogels with Nitrogen Defects and Dedicated Interfacial Structures toward Highly Efficient CO Greenhouse Gas Capture and Separation.

CO capture from flowing flue gases through adsorption technology is essential to reduce the emission of CO to the atmosphere. The rational design of highly efficient carbon-based absorbents with interfacial structures containing interconnected porous structures and abundant adsorption sites might be one of the promising strategies. Here, we report the synthesis of nitrogen-doped carbon aerogels (NCAs) via prepolymerized phenol-melamine-formaldehyde organic aerogels (PMF) by controlling the addition amount of ZnCl and the precursor M/P ratio.

Ionically and Electronically Conductive Phases in a Composite Anode for High-Rate and Stable Lithium Stripping and Plating for Solid-State Lithium Batteries.

Intensive efforts have been taken to decrease the over-potentials of solid-state lithium batteries. Lowering the anode-electrolyte interface resistance is an effective method. Compared to simply improving the interface contact, constructing both ionically and electronically conductive phases within the anode demonstrates superior improvement in reducing the interface resistance and promoting electrochemical stability.

Facile Tailoring of the Electronic Structure and the d-Band Center of Copper-Doped Cobaltate for Efficient Nitrate Electrochemical Hydrogenation.

Electrocatalytic nitrate reduction is an effective strategy to eliminate nitrate's environmental impact and produce high-value-added ammonia products. However, most of the current reports focus on preparation strategies of catalysts, with poor exploration of the mechanism. In this work, we fabricated a binding-free Cu-doped CoO electrode (Cu-CoO) to reveal the structure-activity relationship.

Electroreductive CO coupling of benzaldehyde over SACs Au-NiMnO spinel synergetic composites.

Electroreductive CO coupling provides a prospective strategy for biomass derivative upgrading via reducing the number of oxygen-containing functional groups and increasing their molecular weight. However, exploring superior electrocatalysts with effective reactivity and high selectivity for target products are still a challenge. In this work, single atom Au surface derived NiMnO (SACs Au-NiMnO) spinel synergetic composites were fabricated by a versatile adsorption-deposition method and applied in electroreductive self-coupling of benzaldehyde to dibenzyl ether.

Functionalized Activated Carbon for Competing Adsorption of Volatile Organic Compounds and Water.

The interfacial interaction of activated carbon with volatile organic compounds (VOCs) is seriously affected by water vapor. Therefore, it is vital to enhance the hydrophobic performance of activated carbon for expanding its application in industrial and environmental fields. Herein, a series of hydrophobic activated carbon was fabricated by tailored mixed siloxane and applied in dynamic competitive adsorption at 0, 50, and 90% humidity.

A Porous Nano-Micro-Composite as a High-Performance Bi-Functional Air Electrode with Remarkable Stability for Rechargeable Zinc-Air Batteries.

The development of bi-functional electrocatalyst with high catalytic activity and stable performance for both oxygen evolution/reduction reactions (OER/ORR) in aqueous alkaline solution is key to realize practical application of zinc-air batteries (ZABs). In this study, we reported a new porous nano-micro-composite as a bi-functional electrocatalyst for ZABs, devised by the in situ growth of metal-organic framework (MOF) nanocrystals onto the micrometer-sized BaSrCoFeO (BSCF) perovskite oxide. Upon carbonization, MOF was converted to porous nitrogen-doped carbon nanocages and ultrafine cobalt oxides and CoN nanoparticles dispersing inside the carbon nanocages, which further anchored on the surface of BSCF oxide.

Novel Two-Dimensional AgInS/SnS/RGO Dual Heterojunctions: High Spatial Charge and Toxicity Evaluation.

A single semiconductor employed into photo(electro)catalysis is not sufficient for charge carrier separation. Designing a multiple heterojunction system is a practical method for photo(electro)catalysis. Herein, novel two-dimensional AgInS/SnS/RGO (AISR) photocatalysts with multiple junctions were prepared by a simple hydrothermal method.

Oxygen Vacancy-rich Porous CoO Nanosheets toward Boosted NO Reduction by CO and CO Oxidation: Insights into the Structure-Activity Relationship and Performance Enhancement Mechanism.

Oxygen vacancy-rich porous CoO nanosheets (OV-CoO) with diverse surface oxygen vacancy contents were synthesized via facile surface reduction and applied to NO reduction by CO and CO oxidation. The structure-activity relationship between surface oxygen vacancies and catalytic performance was systematically investigated. By combining Raman, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and O-temperature programmed desorption, it was found that the efficient surface reduction leads to the presence of more surface oxygen vacancies and thus distinctly enhance the surface oxygen amount and mobility of OV-CoO.

The bioelectrochemical synthesis of high-quality carbon dots with strengthened electricity output and excellent catalytic performance.

The emergence of microbial fuel cell (MFC) technology that can effectively recycle renewable energy from organic pollutants has been regarded as a promising and environmentally friendly route that could be widely used in numerous fields. Here, a novel sustainable self-energy conversion system was successfully constructed to renewably synthesize carbon dots (CDs) via in situ coupling with a MFC system. Interestingly, the generation of CDs was found to largely enhance the electricity production performance of the MFC.

Functionalized nitrogen-doped carbon dot-modified yolk-shell ZnFeO nanospheres with highly efficient light harvesting and superior catalytic activity.

Volatile organic compounds (VOCs), as hazardous gaseous pollutants, have attracted much attention due to their potential threat to both human health and the environment. Accordingly, photocatalysis technology is seen as a promising technology to control low concentration VOCs due to its mild operation conditions, low energy consumption, and mineralization ability. However, there are some issues with photocatalysts, such as low light utility and fast photogenerated carrier recombination, which need to be addressed for practical applications.

Rational design and synthesis of highly oriented copper-zinc ferrite QDs/titania NAE nano-heterojunction composites with novel photoelectrochemical and photoelectrocatalytic behaviors.

This work reported that novel highly oriented and vertically aligned stoichiometric copper- and zinc-based ferrites, i.e., Cu0.

Improvement of catalytic activity over Mn-modified CeZrO catalysts for the selective catalytic reduction of NO with NH.

A series of MnCeZrO mixed oxide catalysts were facilely synthesized using the impregnation-NH·HO coprecipitation method and tested for selective catalytic reduction (SCR) of NO with NH. Doping manganese significantly improved the catalytic activity and the best performing SCR catalyst, MnCeZrO, was shown to achieve NO conversion > 80% in the temperature range (60-350 °C), with the denitration effect up to 50% at room temperature (conditions: [NO] = [NH] = 500 ppm, [O] = 5 vol%, He as balance, flow rate  =  100 mL/min, GHSV  =  40, 000 h). Characterization of the catalyst using BET, XRD, XPS, H-TPR, and in-situ FTIR proved that the improved SCR activity may be attributed to the large surface area, great reduction ability and increased amount of surface adsorbed oxygen afforded by the introduction of manganese.

Hierarchically porous cobalt-carbon nanosphere-in-microsphere composites with tunable properties for catalytic pollutant degradation and electrochemical energy storage.

Unreliable energy supply and environmental pollution are two major concerns of the human society in this century. Herein, we report a rational approach on preparation of hierarchically-structured cobalt-carbon composites with tunable properties for a number of applications. A facile hydrothermal treatment of cobalt nitrate and sucrose results in the formation of a metallic cobalt-amorphous carbon composite with cobalt nanospheres anchored homogenously on an amorphous carbon substrate.

B-Site Cation-Ordered Double-Perovskite Oxide as an Outstanding Electrode Material for Supercapacitive Energy Storage Based on the Anion Intercalation Mechanism.

Perovskite oxides are highly promising electrodes for oxygen-ion-intercalation-type supercapacitors owing to their high oxygen vacancy concentration, oxygen diffusion rate, and tap density. Based on the anion intercalation mechanism, the capacitance is contributed by surface redox reactions and oxygen ion intercalation in the bulk materials. A high concentration of oxygen vacancies is needed because it is the main charge carrier.

Submicron sized water-stable metal organic framework (bio-MOF-11) for catalytic degradation of pharmaceuticals and personal care products.

Water-stable and active metal organic frameworks (MOFs) are important materials for mitigation of water contaminants via adsorption and catalytic reactions. In this study, a highly water-stable Co-based MOF, namely bio-MOF-11-Co, was synthesized by a simplified benign method. Moreover, it was used as a catalyst in successful activation of peroxymonsulfate for catalytic degradation of sulfachloropyradazine (SCP) and para-hydroxybenzoic acid (p-HBA) as representatives of pharmaceuticals and personal care products, respectively.

Adsorptive removal of antibiotic sulfonamide by UiO-66 and ZIF-67 for wastewater treatment.

Adsorptive removal of a toxic sulfonamide antibiotic, sulfachloropyradazine (SCP), from aqueous solution was studied on several metal organic frameworks, UiO-66 and ZIF-67, for the first time. UiO-66 exhibited a much higher adsorption capacity than ZIF-67, fast kinetics, and easy regeneration for reuse, demonstrating as a promising adsorbent in wastewater treatment processes. The batch adsorption shows an adsorption capacity of SCP at 417mg/g on UiO-66.

Oxygen Vacancies in Shape Controlled CuO/Reduced Graphene Oxide/InO Hybrid for Promoted Photocatalytic Water Oxidation and Degradation of Environmental Pollutants.

A novel shape controlled CuO/reduced graphene oxide/InO (CuO/RGO/InO) hybrid with abundant oxygen vacancies was prepared by a facile, surfactant-free method. The hybrid photocatalyst exhibits an increased photocatalytic activity in water oxidation and degradation of environmental pollutants (methylene blue and Cr solutions) compared with pure InO and CuO materials. The presence of oxygen vacancies in CuO/RGO/InO and the formation of heterojunction between InO and CuO induce extra diffusive electronic states above the valence band (VB) edge and reduce the band gap of the hybrid consequently.

Metal-free hybrids of graphitic carbon nitride and nanodiamonds for photoelectrochemical and photocatalytic applications.

Graphitic carbon nitride (g-CN) has been considered as a metal-free, cost-effective, eco-friendly and efficient catalyst for various photoelectrochemical applications. However, compared to conventional metal-based photocatalysts, its photocatalytic activity is still low because of the low mobility of carriers restricted by the polymer nature. Herein, a series of hybrids of g-CN (GCN) and nanodiamonds (NDs) were synthesized using a solvothermal method.

FePO based single chamber air-cathode microbial fuel cell for online monitoring levofloxacin.

A bio-electrochemical strategy was developed for constructing a simple and sensitive levofloxacin (LEV) sensor based on a single chamber microbial fuel cell (SC-MFC) using FePO nanoparticles (NPs) as the cathode catalyst instead of traditional Pt/C. In this assembled sensor device, FePO NPs dramatically promoted the electrooxidation of oxygen on the cathode, which helps to accelerate the voltage output from SC-MFC and can provide a powerful guarantee for LEV detection. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to fully characterize the FePO NPs.

Flower-like Cobalt Hydroxide/Oxide on Graphitic Carbon Nitride for Visible-Light-Driven Water Oxidation.

Direct water oxidation via photocatalysis is a four-electron and multiple-proton process which requires high extra energy input to produce free dioxygen gas, making it exacting, especially under visible light irradiation. To improve the oxygen evolution reaction rates (OERs) and utilize more visible light, flower-like cobalt hydroxide/oxide (Fw-Co(OH)/Fw-CoO) photocatalysts were prepared and loaded onto graphitic carbon nitride (g-CN) by a facile coating method in this work. Influenced by the unique three-dimensional morphologies, the synthesized Fw-Co(OH) or Fw-CoO/g-CN hybrids reveal favorable combination and synergism reflected by the modified photoelectric activities and the improved OER performances.

One-pot synthesis of binary metal organic frameworks (HKUST-1 and UiO-66) for enhanced adsorptive removal of water contaminants.

In this study, binary metal organic frameworks (MOFs) with HKUST-1 and UiO-66 have been synthesized in a one-pot process. The synthesized MOFs were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), N adsorption, and thermogravimetric analysis (TGA). The meso-porosity and thermal stability of the binary MOFs were higher than those of single HKUST-1 or UiO-66.