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An optimal W0.4Mo0.6S2 solid solution, equipped with rich intrinsic defects, exhibits excellent stability in both 0.5 M H2SO4 and 2.0 M NaCl, showing negligible activity degradation after continuous 50 hours of working, thereby showing outstanding practical prospects. [ABSTRACT FROM AUTHOR]

A topotactic molecular doping strategy is developed via in situ coupling of dechlorinated carbon with ringed heterocyclic molecules under mild conditions. Specifically, pyridine and pyrrole-converted carbons show pyridinic N to pyrrolic N ratios of 1.82 and 0.13, respectively. The Npyri-C shows much-advanced activity and kinetics for oxygen reduction over the Npyrr-C sample. [ABSTRACT FROM AUTHOR]

Adjusting the micro-environment of highly dispersive metals on carbon supports has been proved to be effective for achieving enhanced electrocatalysis performance. Herein, we delicately design a phosphorus-doped binary NiFe–nitrogen–carbon material (denoted as P-NiFe–NC), taking advantage of the coupling reaction between phenylphosphonamide (P dopant) and formamide (the carbon and nitrogen sources). The XPS N 1s fine scan reveals the strong interplay of N and P by the positively shifted binding energy of pyridinic N species after P incorporation, and the chemical state of Fe species is influenced accordingly. In addition, the P doping can enlarge the specific surface area and increase the meso/macroporosity of NiFe–NC, thus contributing to the enhancement of mass transfer inside the pores. The P-NiFe–NC sample exhibits favorable bifunctional oxygen electrocatalysis performance, rendering an ORR half-wave potential of 0.85 V and an OER potential of 1.69 V@10.0 mA cm−2, superior to those of P-free NiFe–NC. Assembled into Zn–air batteries, P-NiFe–NC delivers a high specific power of 161.36 mW cm−2 and stable charge/discharge for over 100 h (corresponding to 300 cycles). [ABSTRACT FROM AUTHOR]

A binary Mo/Fe-nitrogen-carbon material (MoFe-NC) catalyst was synthesized following the concept of biological nitrogen fixation. The MoFe-NC catalyst demonstrated a maximum N2 reduction faradaic efficiency of 39.9% and a NH3 yield rate of 28.5 μg mgcat−1 h−1 under ambient conditions. [ABSTRACT FROM AUTHOR]

Herein, a F-doped TiO2 (F–TiO2) support significantly weakens the electrooxidative-dissolution and enhances the acidic oxygen evolution reaction (OER) stability of RuOx through the prominent electron-transfer process. Moreover, the electronic structure modulation, dispersing effect and high electrical conductivity of F–TiO2 effectively improve the reaction activity and noble-metal utilization. [ABSTRACT FROM AUTHOR]

Atomic cobalt–nitrogen–carbon (Co–NC) material was synthesized using spent LiCoO2, and contained a heavy Co–N4 loading (1.42 at%). The synthesized Co–NC exhibited high oxygen reduction reaction activity (with onset and half-wave potentials of 0.97 V and 0.87 V, respectively) and robust Al–air battery performance, delivering a specific power of 121.3 mW cm−2. [ABSTRACT FROM AUTHOR]

Direct H2O2 production via the 2e− electrocatalytic oxygen reduction reaction (ORR) offers unique prospects for sanitization and water purification. Search for cheap, effective, selective catalysts for this process is challenging. In this work, a type of doped carbon material with rich edged P atoms co-functionalized with O and N atoms was synthesized via simple solvothermal treatment of P2O5 in formamide, followed by inert annealing. The structures and compositions of O–P/N–C materials were systematically characterized and analyzed. The optimal O–P/N–C900 sample was revealed to contain high P content (2.49 at%) and N content (11.56 at%). Electrochemical measurements revealed that the O–P/N–C900 sample achieved a very high H2O2 yield rate of 698.4 mmol gcat.−1 h−1 and a high Faradaic efficiency of 87% in a H-type cell. The density functional theory (DFT) calculations confirmed that the edged P atom with the co-functionalization of O and N atoms possessed the lowest energy barrier for promoting the selective 2e− ORR, showing good alignment with experiments. This work provides a new strategy for the controllable synthesis of carbon materials decorated with oxygenated heteroatom doping for electrochemical H2O2 synthesis. [ABSTRACT FROM AUTHOR]

We developed a simple method to fabricate a strongly coupled Fe-doped NiS2/MoS2 composite by introducing dual confinement effects during the vapor vulcanization of precursors, which involves the controlled release of metal species and the in situ formation of an N-doped carbon layer. The Fe-doped NiS2/MoS2 composite exhibited a much-enhanced hydrogen/oxygen evolution reaction performance. [ABSTRACT FROM AUTHOR]

The reaction of calcium carbide (CaC2) with water to produce acetylene is common in industrial production, but its side reaction, removal of calcium from CaC2 (also termed de-Ca) to fabricate highly graphitic carbon, is highly overlooked. Herein, we report the synthesis of highly crystalline few-layered graphene by controlling the reaction of tetragonal-phased CaC2 with water at room temperature (20–25 °C). The resulting carbon materials were revealed to be highly graphitic, with ∼3 nm thickness, containing ＞93 at% carbon. Raman spectroscopy evidenced their low defect content with a defect (D)/graphitization (G) ratio of ∼0.07. HRTEM further verified their high graphitization degree. A formation mechanism was proposed: the C22− dumbbells donate their electrons to nearby oxidative species, e.g. H+ in water, followed by topotactic cross-linking to form a conjugated sp2-carbon network. Furthermore, the capability of CaC2 reduction and re-assembly into graphitic carbon was clearly evidenced by reaction with Ag+ in non-aqueous solvent, which resulted in a larger quantity of graphene materials and small-sized Ag nanoparticles. [ABSTRACT FROM AUTHOR]

Carbon nanotube arrays (CNTAs) embedded with transition metal oxides (TMOs) have been considered as effective bifunctional catalysts. However, the hydrophobic nature of CNTAs usually limits the wetting of aqueous solutions containing inorganic precursors of TMOs, which results in poor decoration of TMOs on it. Herein, we report a facile strategy to tune the wettability of 3D CNTAs by controlling the nitrogen-doping degree. Particularly, superhydrophilic nitrogen-doped CNTAs (N-CNTAs) were obtained by using pyridine as the reactant, which allows uniform anchoring of cobalt oxide nanoparticles (NPs) on their surface through a simple self-priming freeze-drying assisted immobilization method. The heteroatom-doping and uniformly distributed cobalt oxide NPs endow the obtained hybrid material (Co3O4/N-CNTAs) with excellent OER and ORR performances, which also demonstrated their high efficiency as bifunctional catalysts for Zn–air batteries. [ABSTRACT FROM AUTHOR]

Aqueous supercapacitors are among the most promising materials for clean and renewable energy storage; however, their utilization for applications is limited by their low specific energy arising from issues due to water splitting. Herein, water splitting-inactive electrode materials of mesoporous carbon were fabricated through the dehalogenation of polyvinylidene fluoride (PVDF) by sodium ethoxide (EtONa). The as-generated EtOH and NaF were demonstrated to facilitate the formation of hierarchical porous carbon based on the bubble and templating effects. Due to full dehalogenation, the resulting carbon materials acquired high contents of carbon without unfavorable alien dopants. The resulting porous, dehalogenated, carbon materials were applied as electrode materials for an aqueous supercapacitor neutral electrolyte. The significantly suppressed water-splitting activity has been addressed in the electrochemical system. Therefore, the open circuit voltage (OCV) could be safely expanded to 2.0 V. Over 94.0% of the capacitance was also maintained after cycling 5000 times at 5.0 A g−1. Our strategy that utilizes water-splitting inactive electrode materials to expand the working window of an aqueous supercapacitor may enable the design of materials for aqueous supercapacitors with higher OCVs over 2.0 V. [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) has attracted huge interest as an energy-efficient and eco-friendly desalination strategy. Its development is presently limited due to the relatively low CDI capacitances of carbon materials. Herein, hierarchical porous carbon materials (HPCs) derived from ethylenediaminetetraacetic acid (EDTA) upon annealing were used, which showed impressive CDI performance with a maximum desalination capacity of 34.27 mg g−1 in 40 mg L−1 NaCl aqueous solution. Such capability was attributed to the appropriate hierarchical pore structure, high specific surface area (2185.71 m2 g−1), large pore volume (1.368 cm3 g−1) and reasonable graphitization degree, which were also confirmed by the high specific capacitances of 182 F g−1 in 1 mol L−1 NaCl and 260 F g−1 in 6 mol L−1 KOH. Since the physisorption capacity was nearly 0, and the regeneration process was facile and complete, such economical HPCs materials show potential for practical desalination applications in the future. Moreover, the HPCs electrodes presented ion selectivity in competitive multi-ionic solutions by kinetic behavior difference or static capacitance difference. [ABSTRACT FROM AUTHOR]

A CoS2 nanopyramid array with a low mass loading (∼0.625 mg cm−2) fabricated on 3D carbon fiber paper exhibits ultrahigh activity towards acidic hydrogen evolution with a low onset potential (∼61 mV) and a small overpotential (∼140 mV) for driving a current density of ∼100 mA cm−2, ascribed to the one-step solvothermal synthesis, unique 3D nanostructure and intrinsic metallic properties of the electrocatalyst. [ABSTRACT FROM AUTHOR]

Carbon coated urchin-like TiO2 microspheres were prepared through coupled hydrolysis of titanium tetrachloride and catalyzed carbonization of glucose. Carbon coating endowed the composite with unusual structural stability at high temperature and reasonable Li-ion battery performance. [ABSTRACT FROM AUTHOR]

Ni0.25Co0.75(OH)2 hierarchical nanowire@nanoplatelet arrays were prepared by an in situ conversion from Ni0.5Co1.5(OH)2CO3 nanowire arrays in a highly concentrated basic solution at room temperature. These unique hierarchical nanoarrays showed a 7 times larger areal capacitance and better rate capability than the precursive one-dimensional nanowire arrays. [ABSTRACT FROM AUTHOR]

To date, “metal-free” catalysts originating from graphene and CNTs have been revealed to contain metal impurities. Many types of such “metal-free” carbons have been synthesized by metal-involving methods, and it is urgent to confirm the origin of the catalytic performance. Herein, we verified that residual metals were inevitably present in these N-doped carbons and the catalytic performance for the hydrogen evolution reaction (HER) was due to the remaining metals, present at only a ppm level. [ABSTRACT FROM AUTHOR]

A binary Mo/Fe-nitrogen-carbon material (MoFe-NC) catalyst was synthesized following the concept of biological nitrogen fixation. The MoFe-NC catalyst demonstrated a maximum N2 reduction faradaic efficiency of 39.9% and a NH3 yield rate of 28.5 μg mgcat−1 h−1 under ambient conditions. [ABSTRACT FROM AUTHOR]

Atomic cobalt–nitrogen–carbon (Co–NC) material was synthesized using spent LiCoO2, and contained a heavy Co–N4 loading (1.42 at%). The synthesized Co–NC exhibited high oxygen reduction reaction activity (with onset and half-wave potentials of 0.97 V and 0.87 V, respectively) and robust Al–air battery performance, delivering a specific power of 121.3 mW cm−2. [ABSTRACT FROM AUTHOR]

An optimal W 0.4 Mo 0.6 S 2 solid solution, equipped with rich intrinsic defects, exhibits excellent stability in both 0.5 M H 2 SO 4 and 2.0 M NaCl, showing negligible activity degradation after continuous 50 hours of working, thereby showing outstanding practical prospects.

A binary Mo/Fe-nitrogen-carbon material (MoFe-NC) catalyst was synthesized following the concept of biological nitrogen fixation. The MoFe-NC catalyst demonstrated a maximum N 2 reduction faradaic efficiency of 39.9% and a NH 3 yield rate of 28.5 μg mg cat -1 h -1 under ambient conditions.

Atomic cobalt-nitrogen-carbon (Co-NC) material was synthesized using spent LiCoO 2 , and contained a heavy Co-N 4 loading (1.42 at%). The synthesized Co-NC exhibited high oxygen reduction reaction activity (with onset and half-wave potentials of 0.97 V and 0.87 V, respectively) and robust Al-air battery performance, delivering a specific power of 121.3 mW cm -2 .

We developed a simple method to fabricate a strongly coupled Fe-doped NiS 2 /MoS 2 composite by introducing dual confinement effects during the vapor vulcanization of precursors, which involves the controlled release of metal species and the in situ formation of an N-doped carbon layer. The Fe-doped NiS 2 /MoS 2 composite exhibited a much-enhanced hydrogen/oxygen evolution reaction performance.

Carbon coated urchin-like TiO2 microspheres were prepared through coupled hydrolysis of titanium tetrachloride and catalyzed carbonization of glucose. Carbon coating endowed the composite with unusual structural stability at high temperature and reasonable Li-ion battery performance.