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Exploring efficient non-noble metal catalysts for the hydrogen evolution reaction (HER) will contribute to the development of clean and green energy technologies. Herein, we adopted a "waste utilization" strategy by using readily available and inexpensive coconut shell waste as a carbon source to synthesize carbon materials anchored with a Cu7Co alloy (Cu7Co/C) as a potential electrocatalyst for the hydrogen evolution reaction (HER). Utilizing a combination of hydrothermal and pyrolysis methods, the synthesized Cu7Co/C catalyst showcases superior HER electrocatalytic performance in alkaline solutions, with an overpotential of 134 mV at 10 mA cm−2 and a Tafel slope of 94 mV dec−1. The alloying of Cu and Co within Cu7Co/C markedly improves charge transfer capabilities, enhancing HER electrocatalysis. This research underscores the exceptional catalytic performance and stability of Cu7Co/C nanocomposites in alkaline media for the HER, attributed to a synergistic effect between the carbon derived from coconut shells and the bimetallic Cu7Co alloy. [ABSTRACT FROM AUTHOR]

The electrocatalytic reduction of nitrogen (N2) is considered as a carbon-free and energy-saving strategy to replace the traditional Haber–Bosch technique for artificial preparation of NH3. However, the electrocatalytic efficiency of current catalysts for nitrogen reduction reaction (NRR) are drastically limited by the strong N≡N (941.3 kJ mol−1) triple bond in the N2 molecule. Herein, we prepare MoN nanorods supported on carbon fabric cloth (MoN/CFC) via seed-assisted hydrothermal and ammonolysis methods. SEM, XRD, XPS, and TEM techniques were conducted to investigate the structures and morphologies of MoN nanorods. The MoN/CFC electrode provides an optimal NH3 yield of 6.31 μmol h−1 cm−2 (107.3 μg h−1 cm−2) and the corresponding faradaic efficiency (FE) of 12.84% (−0.45 V vs. RHE) with excellent electrocatalytic stability towards NRR under a 0.1 M KOH electrolyte, and a potential mechanism is proposed. [ABSTRACT FROM AUTHOR]

Here, we report the synthesis of Cu-doped CeO2 nanorods (denoted as Cu-CeO2-x, x represents the mass content (wt%) of the doped Cu) by a facile hydrothermal method, followed by thermal treatment in an H2/Ar atmosphere. As the electrocatalyst, Cu-CeO2-3.9 with a large surface area of 95.2 m2 g−1 and mesoporous structure exhibits high electrocatalytic activity toward the N2 reduction reaction (NRR), delivering an NH3 yield rate of 5.3 × 10−10 mol s−1 cm−2 and a faradaic efficiency of 19.1% at −0.45 V (vs. RHE) in a 0.1 M Na2SO4 electrolyte (pH = 6.3), much higher than the NRR performance achieved with pure CeO2 nanorods. The Cu doping can effectively tune the concentration of multiple oxygen vacancies in CeO2, thus resulting in significantly improved NRR activity. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract We investigate the possibility of utilizing benzyl alcohol oxidation reaction to replace sluggish oxygen evolution reaction (OER) for the charging process in a rechargeable zinc-air battery, catalyzed by NiCo alloy nanoparticles supported on activated carbon (NiCo/AC) with the multifunctional electrocatalytic activities of the oxygen reduction, oxygen evolution and benzyl alcohol oxidation reactions. As an electrocatalyst for the oxygen reduction reaction (OER), NiCo/AC exhibits superior catalytic activity with an onset potential of 0.85 V (vs. RHE), a half-wave potential of 0.74 V (vs. RHE) and a large limiting current density of 4.65 mA cm−2 at 0.2 V (vs. RHE). Moreover, NiCo/AC also demonstrates the electrocatalytic oxidation activities toward water and benzyl alcohol, moreover, the benzyl alcohol oxidation reaction is more thermodynamically and kinetically favourable with 254 mV smaller overpotential than water oxidation at 10 mA cm−2. Owing to these advantages, NiCo/AC as air cathode material is assembled into a home-made rechargeable zinc-air battery, resulting an almost 200 mV lower charging voltage at the current density of 50 mA cm−2 in the presence of 0.1 M benzyl alcohol compared to the battery without benzyl alcohol, consequently obtaining 10.5% energy saving at the charging current density of 50 mA cm−2 with high durability. [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) has been a promising technique to obtain fresh water by electrosorption of charged ionic species in seawater/brackish water. Its performance is highly dependent on the physical and chemical properties of CDI electrode materials. Herein, N-doped porous carbon (NPC) with a N content of 1.66 at.% was fabricated using soybean shell as starting material by a facile pyrolysis approach with the assistance of KHCO 3 in N 2 atmosphere. The as-prepared NPC with porous structure and high surface area (1036.2 m 2  g −1 ) was further functionalized with sulfonic groups in an aryl diazonium salt solution to obtain sulfonyl functionalized NPC (S-NPC) with a surface area of 844.0 m 2  g −1 . S-NPC as cathode material was assembled into an asymmetric CDI device with aminated activated carbon (A-AC) as anode material, exhibiting superior CDI performance with an adsorption capacity of 15.5 mg g −1 and an average adsorption rate of 0.44 mg g −1  min −1 in 40 mg L −1 NaCl solution at an applied voltage of 1.2 V. As a proof of concept study, such configured CDI device was also powered for the first time by a Zn-air battery made from NPC with an open-circuit voltage of 1.28 V owing to N doping in soybean shell derived porous carbon with superior oxygen reduction reaction (ORR) activity, delivering an impressive CDI performance with an adsorption capacity of 15.8 mg g −1 and an average adsorption rate of 0.37 mg g −1  min −1 in 40 mg L −1 NaCl solution. This superior CDI performance can be due to S-NPC with high surface area, porous structure and surface rich negative charges resulted from sulfonyl functionalization, favourable for adsorption active sites exposure and mass transport of Na + ions. [ABSTRACT FROM AUTHOR]

The ultrafine Ni nanoparticles supported on carbon nanofiber are prepared via adsorption-pyrolyzation strategy and used as air electrodes to assemble flexible solid-state Zn-air battery. Development of well-designed bifunctional electrocatalysts with high activity for OER (oxygen evolution reaction) and ORR (oxygen reduction reaction) are a crucial topic owing to their promising applications in rechargeable Zinc (Zn)-air battery. Herein, a facile adsorption-pyrolyzation strategy is proposed for preparing ultrafine Ni nanoparticles anchored on carbon nanofiber (Ni/CNF), which derives from pyrolyzation of bacterial cellulose (BC) (with pre-adsorbed of Ni2+) via a two-step heat-treatment procedure (firstly 360 ℃, and then 750 ℃) (Ni/CNF-750) and used as an excellent oxygen electrocatalyst for flexible all solid-state Zn-air cell. The resultant ultrafine Ni/CNF-750 with plentiful pore structure and relatively high specific surface area of 449.0 m2 g−1, delivering overpotential of 293 mV at current density of 10 mA cm−2 for OER, obtaining an onset potential of 0.93 V vs. RHE and half-wave potential of 0.76 V vs. RHE for ORR. Moreover, a home-made flexible all solid-state battery is constructed by using Ni/CNF-750 as air electrodes, which provides a power density of 56.8 mW cm−2 and wonderful cycling durability with maintaining 50 cycles, and can drive a light-emitting-diode (LED) device. Our work may provides a reliable approach for fabricating ultrafine metal nanoparticles anchored on carbon based substrate with high activity for next-generation energy conversion and storage devices. [ABSTRACT FROM AUTHOR]

Transition metal-based oxides have been reported as an important family of electrocatalysts for water splitting owing to their possible large-scale applications that are highly desirable for the hydrogen generation industry. Herein, we report a facile method for the preparation of phosphate-decorated NiFe oxides on nickel foam as efficient oxygen evolution reaction (OER) electrocatalysts for water oxidation. The OER electrocatalysts were developed through the pyrolysis of MIL(Fe) metal–organic frameworks (MOFs), which were modified with Ni and P species. It was found that the formation of NiO on the Fe2O3 surface (NiO@Fe2O3) can enrich electrocatalytic active sites for the OER. Meanwhile, the incorporation of P into NiO@Fe2O3 (Px-NiO@Fe2O3) creates abundant oxygen vacancies, which facilitates the surface charge transfer for OER electrocatalysis. Benefiting from the structure and composition advantages, P2.0-NiO@Fe2O3/NF exhibits the best performance for OER electrocatalysis among other prepared electrocatalysts, with an overpotential of 208 mV at the OER current density of 10 mA cm−2 and a small Tafel slope of 69.64 mV dec−1 in 1 M KOH solution. Additionally, P2.0-NiO@Fe2O3/NF shows an outstanding durability for the OER electrocatalysis, maintaining the OER current density above 20 mA cm−2 for more than 100 h. [ABSTRACT FROM AUTHOR]

Efficient and robust electrocatalysts towards the oxygen evolution reaction (OER) are highly desirable in electrochemical systems for applications including water splitting and metal-air batteries. Herein, we report the preparation of an amorphous FeCoNiMnCr high-entropy alloy (HEA) on the surface of flower-like 2H-MoS2 (FeCoNiMnCr@MoS2) as a highly efficient electrocatalyst for the OER. The flower-like 2H-MoS2 is prepared on the flexible conductive carbon cloth (MoS2-CC) via a hydrothermal method, and subsequently the amorphous FeCoNiMnCr HEA is loaded on the surface of 2H-MoS2via an electrodeposition method to form FeCoNiMnCr@MoS2-CC electrocatalysts. Owing to the unique microstructure of 2H-MoS2 and abundant active sites of FeCoNiMnCr HEA, the FeCoNiMnCr@MoS2-CC electrocatalysts exhibit significantly improved OER electrocatalytic performances with a low overpotential of 210 mV at a current density of 10 mA cm−2 and a small Tafel slope of 40.3 mV dec−1 in 1.0 M KOH solution. Moreover, it shows excellent stability for OER electrocatalysis with the potential barely increased for at least 50 h. This work sheds light on the development of highly efficient OER electrocatalysts based on HEAs. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting as an environmentally friendly method to produce clean H2 has attracted wide attention. However, efficient improvement of the performance of the oxidation half-reaction during water splitting, thus enhancing H2 evolution efficiency, has become an urgent issue. Herein, non-precious metal Co0.83Ni0.17 alloy nanoparticles on activated carbon (Co0.83Ni0.17/AC) have been successfully fabricated by a simple thermal-treatment method. The resulting Co0.83Ni0.17/AC with a dominant alloy particle size of 45 nm exhibits a microporous and mesoporous structure with a surface area of 159.2 m2 g−1. As an electrocatalyst, the as-prepared Co0.83Ni0.17/AC demonstrates bifunctional electrocatalytic activity toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media, delivering overpotentials of 193 and 325 mV at 10 mA cm−2, respectively. Importantly, it is found that the electrocatalytic oxidation of benzyl alcohol to benzoic acid on Co0.83Ni0.17/AC is more favourable than the OER process, with almost 224 mV less overpotential at 10 mA cm−2 and 96% faradaic efficiency at 1.425 V vs. RHE (passing charge amount of ∼40C). As a simultaneous anode and cathode electrocatalyst for water splitting, Co0.83Ni0.17/AC displays a H2 generation rate of 8.98 μmol min−1 in 1.0 M KOH solution containing 10 mM benzyl alcohol, almost 1.4 times that obtained by an OER-introduced water splitting system, with near 98% faradaic efficiency for H2. This work would be helpful to develop low-cost and abundant bifunctional electrocatalysts for electrocatalytic organic synthesis and simultaneously improving H2 generation from water splitting. [ABSTRACT FROM AUTHOR]

A Mn-incorporated Ni(OH)2/carbon fiber cloth (Mn-Ni(OH)2/CFC) fabricated via a room-temperature solution route exhibited superior electrocatalytic activities of the oxygen reduction and urea oxidation reactions, delivering 12–21% energy saving in the charging process of Mn-Ni(OH)2/CFC assembled Zn–air batteries in the presence of 0.5 M urea compared to the battery without urea. [ABSTRACT FROM AUTHOR]

The development of efficient and stable oxygen evolution reaction (OER) electrocatalysts with nonprecious materials is still a great challenge for the hydrogen-based energy industry. Here, we report the rational design and effective synthesis of hierarchical porous medium-entropy alloys (MEAs) as promising electrocatalysts for OER via a solution combustion method. Owing to the compositional advantages and unique hierarchical porous structure, the as-prepared CoNiFeCu 0.1 MEA on nickel foam (CoNiFeCu 0.1 @NF) shows superior electrocatalytic performance for OER with an overpotential of about 255 mV at 10 mA cm−2 and a small Tafel slope of 42.7 mV dec−1 in 1.0 M KOH solution. Moreover, it is revealed that the alloying of element Cu in CoNiFe MEA can significantly enhance the charge transfer ability for OER electrocatalysis. The present work shows the hierarchical porous MEAs prepared by solution combustion method have great potential as efficient and robust electrocatalysts for water oxidation in alkaline medium. [Display omitted] • Hierarchical porous medium-entropy alloys are prepared by solution combustion method. • The alloying of Cu in CoNiFe alloy can improve electrocatalytic performances. • CoNiFeCu 0.1 @NF is stable for OER electrocatalysis for 100 h in alkaline medium. • It has an overpotential of 255 mV at 10 mA cm−2 and a Tafel slope of 42.7 mV dec−1. [ABSTRACT FROM AUTHOR]

Correction for ‘Electrocatalytic oxidation of benzyl alcohol for simultaneously promoting H2 evolution by a Co0.83Ni0.17/activated carbon electrocatalyst’ by Guoqiang Liu et al., New J. Chem., 2018, 42, 6381–6388. [ABSTRACT FROM AUTHOR]

Electrosynthesis of NH3 through the N2 reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy‐ and capital‐intensive Haber–Bosch process. Herein, a room‐temperature spontaneous redox approach to fabricate a core–shell‐structured Au@CeO2 composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as‐synthesized Au@CeO2 possesses a surface area of 40.7 m2 g−1 and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH3 yield rate of 28.2 μg h−1 cm−2 (10.6 μg h−1 mg−1cat., 293.8 μg h−1 mg−1Au) and a faradaic efficiency of 9.50 % at −0.4 V versus a reversible hydrogen electrode in 0.01 m H2SO4 electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO2 nanoparticle shell of Au@CeO2; these are favorable for N2 adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO2 nanoparticle shell, combined with the Au nanoparticle core of Au@CeO2, are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N2 into NH3. [ABSTRACT FROM AUTHOR]

Abstract Here we report that the plasma-etching processed commercial titanium nitride (TiN-PE, PE represents plasma-etching) that was first treated by ball-milling method (TiN BM, BM represents ball-milling) is highly electrochemically active for the nitrogen (N 2) reduction reaction (NRR) to NH 3. The results demonstrate that the TiN-PE as NRR electrocatalyst can deliver a yield rate of NH 3 of 3.32 × 10−10 mol s−1 cm−2 (4.1 mg h−1 g cat. −1) with a Faradaic efficiency of 9.1% at −0.6 V (vs. RHE) in 0.1 M Na 2 SO 4 solution (pH = 3.2). The X-ray photoelectron spectroscopy (XPS) analysis indicates that the titanium oxynitride (TiO x N y) with high oxygen content on TiN surface was significantly enhanced by this plasma-etching approach, which is electrocatalytically active species for NRR. The 15N isotopic labeling experimental results using 15N 2 as the feeding gas verify that the syntheized NH 3 product during NRR is composed of 15N in 15NH 4 + (the enrichement of 64%) and 14N in 14NH 4 + (the enrichment of 36%), indicating that the NRR process follows the Mars–van Krevelen mechanism. Graphical abstract Unlabelled Image Highlights • Commercial TiN was treated by a combined approach of ball-milling and plasma etching. • Titanium oxynitride (TiO x N y) with high oxygen content was obtained on TiN surface after plasma-etching treatment. • TiO x N y is the active phase of electrocatalytic N 2 reduction reaction to ammonia. [ABSTRACT FROM AUTHOR]

Ni 2 P nanocrystallines grown on carbon fiber cloth (Ni 2 P/CFC) was successfully achieved by a facile vapour-phase hydrothermal method. The as-prepared Ni 2 P/CFC, as an electrocatalyst, exhibited superior electrocatalytic activities toward urea oxidation reaction (UOR) with a potential of 1.42 V ( vs. RHE) delivering a current density of 10 mA cm −2 and hydrogen evolution reaction (HER) with overpotentials of 90 and 155 mV at current densities of 10 and 100 mA cm −2 in alkaline media. On this basis, a Ni 2 P/CFC constructed two-electrode system for high-efficiency H 2 production and simultaneous urea decomposition was therefore established using commercial urea as reaction source. Besides, such two-electrode system as proof of concept study was also evaluated using human urine as urea source for highly efficient H 2 generation with a rate of 0.35 μM min −1 at an applied potential of 1.48 V, delivering a current density of 10 mA cm −2 . [ABSTRACT FROM AUTHOR]

Calcined magnesia in a designed formulation was prepared with magnesite tailings below 1100°C to compensate for the autogenous shrinkage of steam-cured Portland cement and fly ash pastes with low water/binder ratios. The morphology and hydration properties of the light calcined magnesite tailings (LCM) were studied by field-emission source scanning electron microscopy (FESEM) and isothermal calorimetry. The hydration of magnesium oxide in paste and the microstructure of the paste were determined by thermogravimetric and differential thermal analysis, mercury intrusion porosimetry, FESEM and backscattered SEM. The results show that the hydration activity of LCM can be easily designed by regulating the calcining temperature. Both early age (7 d) and later age (90 d) autogenous shrinkage of steam-cured cement paste could be partially compensated when adding 4 wt% LCM prepared at 850°C (M85), probably due to the locally restrained continued slow hydration of magnesium oxide in M85. [ABSTRACT FROM AUTHOR]

With the development of microelectronic industry, low dielectric-constant insulating materials with high temperature performance and photopatternability have aroused interest. In this work, a kind of benzocyclobutene/vinylphenyl-introduced polycarbosilanes (PVBCS) were synthesized by H 2 PtCl 6 catalyzed ring-opening copolymerization of 4-(1-methylsilacyclobutyl) benzocyclobutene (4-MSCBBCB) and 1-methyl-1-(4-vinylphenyl) silacyclobutane (1-MVPSCB). By directly introducing photo-active groups on the pendants of polycarbosilanes, the PVBCS was endowed with photopatternability without additionally using any photo-initiators or photo-crosslinkers. DSC and FTIR characterization demonstrated that the PVBCS was UV&thermally curable. The UV curing was conducted at ambient temperature and the thermally curing was performed above 200 °C. TGA curves of the cured PVBCS indicated that the 5% weight loss temperature is 473 °C, which is above the required temperature limit. The cured PVBCS also has low dielectric constant of 2.32–2.40 in the range of 1 k∼1 MHz. The high temperature performance and low-dielectric constant could be attributed to the polycarbosilane main-chain structure and the benzocyclobutene-based cross-linked structure. [ABSTRACT FROM AUTHOR]

In article number 1803935, Haimin Zhang, Huijun Zhao and co‐workers enhance the ambient NH3 electrosynthesis performance of MoS2 dramatically by in‐operando created Li–S interactions through effectively suppressed HER activity at S‐edge/Mo‐edge sites, and simultaneously increased N2 adsorption capability and boosted NRR catalytic activity on Mo‐edge sites. [ABSTRACT FROM AUTHOR]

The Haber‐Bosch process can be replaced by the ambient electrocatalytic N2 reduction reaction (NRR) to produce NH3 if suitable electrocatalysts can be developed. However, to develop high performance N2 fixation electrocatalysts, a key issue to be resolved is to achieve efficient hydrogenation of N2 without interference by the thermodynamically favored hydrogen evolution reaction (HER). Herein, in‐operando created strong Li–S interactions are reported to empower the S‐rich MoS2 nanosheets with superior NRR catalytic activity and HER suppression ability. The Li+ interactions with S‐edge sites of MoS2 can effectively suppress hydrogen evolution reaction by reducing H* adsorption free energy from 0.03 to 0.47 eV, facilitate N2 adsorption by increasing N2 adsorption free energy from –0.32 to –0.70 eV and enhance electrocatalytic N2 reduction activity by decreasing the activation energy barrier of the reaction control step (*N2 → *N2H) from 0.84 to 0.42 eV. A NH3 yield rate of 43.4 μg h−1 mg−1 MoS2 with a faradaic efficiency (FE) of 9.81% can be achieved in presence of strong Li–S interactions, more than 8 and 18 times by the same electrocatalyst in the absence of Li–S interactions. This report opens a new way to design and develop catalysts and catalysis systems. The ambient NH3 electrosynthesis performance of MoS2 is dramatically enhanced by in‐operando created Li–S interactions through effectively suppressed hydrogen evolution reaction activity at S‐edge/Mo‐edge sites, and simultaneously increased N2 adsorption capability and boosted N2 reduction reaction catalytic activity on Mo‐edge sites. The reported in‐operando formation of catalytic active structures via catalyst–electrolyte interactions opens a new way to develop catalysts and catalysis systems. [ABSTRACT FROM AUTHOR]