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Water pollution caused by the massive use of medicines has caused significant environmental problems. This work first reports the synthesis and characterization of the Cu 7 S 4 /CuCo 2 O 4 (CS/CCO) yolk-shell microspheres via hydrothermal and annealing methods, and then investigates their photocatalytic performance in removing organic water pollutants. The 10-CS/CCO composite with yolk-shell microspheres exhibits the highest photodegradation rate of carbamazepine (CBZ), reaching 96.3% within 2 h. The 10-CS/CCO also demonstrates more than two times higher photodegradation rates than the pure (Cu 7 S 4 ) CS and (CuCo 2 O 4 ) CCO. This outstanding photocatalytic performance can be attributed to the unique yolk-shell structure and the Z-scheme charge transfer pathway, reducing multiple reflections of the acting light. These factors enhance the light absorption efficiency and efficiently transfer photoexcited charge carriers. In-depth, photocatalytic degradation pathways of CBZ are systematically evaluated via the identification of degradation intermediates with Fukui index calculation. The insights gained from this work can serve as a guideline for developing low-cost and efficient Z-scheme photocatalyst composites with the yolk-shell structure., (© 2023 Wiley-VCH GmbH.)

Piezocatalysis, a newly emerging catalysis technology that relies on the piezopotential and piezoelectric properties of the catalysts, is attracting unprecedented research enthusiasm for applications in energy conversion, organic synthesis, and environmental remediation. Despite the rapid development in the past three years, the mechanism of piezocatalysis is still under debate. A fundamental understanding of the working principles of this technology should enable the future design and optimization of piezocatalysts. Herein, we provide an overview of the two popular theories used to explain the observed piezocatalysis: energy band theory and screening charge effect. A comprehensive discussion and clarification of the differences, relevance, evidence, and contradiction of the two mechanisms are provided. Finally, challenges and perspectives for future mechanistic studies are highlighted. Hopefully, this Review can help readers gain a better understanding of piezocatalysis and enable its application in their own research., (© 2021 Wiley-VCH GmbH.)

Direct conversion of syngas to dimethyl ether (DME) through the intermediate of methanol allows more efficient DME production in a simpler reactor design relative to the conventional indirect route. Although Cu/ZnO-based multicomponent catalysts are highly active for methanol synthesis in this process, the sintering issue of Cu during the prolonged reaction generally deteriorates their performance. In this work, Cu/ZnO catalysts in a novel octahedron structure are prepared by a two-step pyrolysis of Zn-doped Cu-BTC metal-organic framework (MOF) in N 2 and air. The catalyst CZ-350/A, hybrid of MOF-derived Cu/ZnO sample CZ-350 and γ-Al 2 O 3 for methanol dehydration, displays the best activity for DME formation (7.74% CO conversion and 70.05% DME selectivity) with the lowest deterioration rate over 40 h continuous reaction. Such performance is superior to its counterpart CZ-CP/A made via the conventional coprecipitation method. This is mainly due to the confinement of Cu nanoparticles within the octahedron matrix hindering their migration and aggregation. Besides, partial reduction of ZnO in the activated CZ-350 prompts the formation of Cu + -O-Zn, further facilitating the DME production with the highest selectivity compared to literature results. The results clearly indicate that Cu and ZnO distribution in the catalyst architecture plays an important role in DME formation., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen production from renewable electricity relies upon the development of an efficient alkaline water electrolysis device and, ultimately, upon the availability of low cost and stable electrocatalysts that can promote oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Normally, different electrocatalysts are applied for HER and OER because of their different reaction intermediates and mechanisms. Here, the synthesis of a heterostructured CoP@a-CoOx plate, which constitutes the embedded crystalline cobalt phosphide (CoP) nanoclusters and amorphous cobalt oxides (CoOx) nanoplates matrix, via a combined solvothermal and low temperature phosphidation route is reported. Due to the presence of synergistic effect between CoP nanoclusters and amorphous CoOx nanoplates in the catalyst, created from the strong nanointerfaces electronic interactions between CoP and CoOx phases in its heterostructure, this composite displays very high OER activity in addition to favorable HER activity that is comparable to the performance of the IrO 2 OER benchmark and approached that of the Pt/C HER benchmark. More importantly, an efficient and stable alkaline water electrolysis operation is achieved using CoP@a-CoOx plate as both cathode and anode as evidenced by the obtainment of a relatively low potential of 1.660 V at a 10 mA cm -2 current density and its marginal increase above 1.660 V over 30 h continuous operation.

Because of their structural and compositional flexibility, perovskite oxides represent an attractive alternative electrocatalyst class to precious metals for the oxygen reduction reaction (ORR); an important reaction in fuel cells and metal-air batteries. Partial replacement of the original metal cation with another cation, namely, doping, can be used to tailor the ORR activity of perovskite, for which a metal has been exclusively used as the dopant component in the past. Herein, phosphorus is proposed as a non-metal dopant for the cation site to develop a new perovskite family with the formula of La 0.8 Sr 0.2 Mn 1-x P x O 3-δ (x=0, 0.02, 0.05, and 0.1; denoted as LSM, LSMP0.02, LSMP0.05, and LSMP0.1, respectively). Powder XRD patterns reveal that the solubility of phosphorus in the perovskite structure is around 0.05. Rotating ring-disk electrode experiments in the form of linear-sweep voltammetry scans demonstrated the best ORR performance for LSMP0.05, and also revealed close to a four-electron ORR pathway for all four compositions. A chronoamperometric test (9000 s) and 500 cycle accelerated durability test demonstrated higher durability for LSMP0.05 relative to that of LSM and the commercial 20 wt % Pt/C catalyst. The higher ORR activity for LSMP0.05 is attributed to the optimised average valence of Mn, as evidenced by combined X-ray photoelectron spectroscopy and soft X-ray absorption spectroscopy data. Doping phosphorus into perovskites is an effective way to develop high-performance electrocatalysts for ORR., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Solid-oxide fuel cells (SOFCs) are electricity generators that can convert the chemical energy in various fuels directly to the electric power with high efficiency. Recent advances in materials and related key components for SOFCs operating at ≈500 °C are summarized here, with a focus on the materials, structures, and techniques development for low-temperature SOFCs, including the analysis of most of the critical parameters affecting the electrochemical performance of the electrolyte, anode, and cathode. New strategies, such as thin-film deposition, exsolution of nanoparticles from perovskites, microwave plasma heating, and finger-like channeled electrodes, are discussed. These recent developments highlight the need for electrodes with higher activity and electrolytes with greater conductivity to generate a high electrochemical performance at lower temperatures., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The vital role of ethylenediaminetetraacetic acid on the structure and the oxygen reduction reaction activity of the non-precious-metal-based pyrolyzed catalyst is reported and elaborated. The resultant catalyst can overtake the performance of commercial Pt/C catalyst in an alkaline medium.

Oxygen selective membranes with enhanced oxygen permeability and CO2 resistance are highly required in sustainable clean energy generation technologies. Here, we present novel, cobalt-free, SrFe1-x Tax O3-δ (x=0, 0.025, 0.05, 0.1, 0.2) perovskite membranes. Ta-doping induced lattice structure progression from orthorhombic (x=0) to cubic (x=0.05). SrFe0.95 Ta0.05 O3-δ (SFT0.05) showed the highest oxygen flux rates reaching 0.85 mL min(-1) cm(-2) at 950 °C on a 1.0 mm-thick membrane. Surface decoration can increase the permeation rate further. Ta inclusion within the perovskite lattice of SrFeO3-δ (SF) enhanced the CO2 resistance of the membranes significantly as evidenced by the absence of the carbonate functional groups on the FTIR spectrum when exposed to CO2 atmosphere at 850 °C. The CO2 resistance of Ta-doped SF compounds correlates with the lower basicity and the higher binding energy for the lattice oxygen. SFT0.05 demonstrated high stability during long-term permeation tests under 10% CO2 atmosphere., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Increasing energy demands have stimulated intense research activity on cleaner energy conversion such as regenerative fuel cells and reversible metal-air batteries. It is highly challenging but desirable to develop low-cost bifunctional catalysts for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), the lack of which is currently one of the major limiting components towards commercialization of these technologies. Here, we have conducted a systematic study on the OER and ORR performances of the Ruddlesden-Popper family of La(n+1)Ni(n) O(3n+1) (n=1, 2, 3, and ∞) in an alkaline medium for the first time. It is apparent that the Ni-O bond lengths and the hyperstoichiometric oxides in the rock-salt layers correlate with the ORR activities, whereas the OER activities appear to be influenced by the OH(-) content on the surface of the compounds. In our case, the electronic configuration fails to predict the electrocatalytic activity of these compounds. This work provides guidelines to develop new electrocatalysts with improved performances., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)