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The electrochemical desalination technique is recognized as a promising solution to alleviate freshwater shortages, challenges yet persists in achieving optimal energy efficiency and cost‐effectiveness. Herein, a hybrid acid/alkali zinc air desalination battery (hAA‐ZADB) capable of concurrent desalination and high‐power density is reported. To improve cathodic efficiency and cost‐effectiveness, an electrocatalyst with dual atomic Fe–Mn sites on porous dodecahedral carbon (Mn‐Fe/p‐DC) is fabricated through a simple direct pyrolysis strategy for oxygen reduction reaction (ORR). The Mn–Fe/p‐DC‐900 electrocatalyst demonstrates exceptional electrocatalytic activity (E1/2 = 0.8 V in 0.5 m H2SO4) for ORR. This innovative hybrid acid/alkali cell design, coupled with advanced electrocatalysts, empowers the hAA‐ZADB system to achieve outstanding performance benchmarks with a high open circuit voltage of 2.22 V, an impressive power density of 375 mW cm−2, and notably elevated energy output of 106.9 kJ mol−1 even at a current density of 100 mA cm−2 during desalination. Distinguishing this work is its additional functionality, evident in a rapid salt removal rate of 3.64 mg cm−2 min−1 during desalination, achieving an impressive 88.67% removal of 0.6 M NaCl. This study highlights the promising potential of employing metallic air batteries for a self‐powered desalination technique applicable to specific scenarios. [ABSTRACT FROM AUTHOR]

Transition metal single atoms anchored on nitrogen‐doped carbon (M‐N‐C) matrix with M‐N‐C active sites have shown to be promising catalysts for both hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). Herein, a hybrid catalyst with low‐level loading of atomic Pt and Co species encapsulated in nitrogen‐doped graphene (Pt@CoN4‐G) is developed. The Pt@CoN4‐G shows low overpotential for HER in wide‐pH electrolyte and manifests improved mass activity with almost eight times greater than that of Pt/C at an overpotential of 50 mV. The Pt@CoN4‐G also exhibits a top‐level ORR activity (half‐wave potential, E1/2 = 0.893 V) and robust stability (>200 h) in alkaline medium. Using theoretical calculations and comprehensive characterizations , the strong metal–support interactions between Pt species and CoN4‐G support and synergistical cooperation of multiple active sites are clarified. A flow alkali‐Al/acid hybrid fuel cell using Pt@CoN4‐G as cathode catalyst delivers a large power density of 222 mW cm−2 with excellent stability to achieve simultaneously hydrogen evolution and electricity generation. In addition, Pt@CoN4‐G endows a flow Zn‐air battery with high power density (316 mW cm−2), good stability under large current density (>100 h at 100 mA cm−2), and long cycle life (over 600 h at 5 mA cm−2). [ABSTRACT FROM AUTHOR]

Electrosynthesis of H2O2 has great potential for directly converting O2 into disinfectant, yet it is still a big challenge to develop effective electrocatalysts for medical‐level H2O2 production. Herein, we report the design and fabrication of electrocatalysts with biomimetic active centers, consisting of single atomic iron asymmetrically coordinated with both nitrogen and sulfur, dispersed on hierarchically porous carbon (FeSA‐NS/C). The newly‐developed FeSA‐NS/C catalyst exhibited a high catalytic activity and selectivity for oxygen reduction to produce H2O2 at a high current of 100 mA cm−2 with a record high H2O2 selectivity of 90 %. An accumulated H2O2 concentration of 5.8 wt.% is obtained for the electrocatalysis process, which is sufficient for medical disinfection. Combined theoretical calculations and experimental characterizations verified the rationally‐designed catalytic active center with the atomic Fe site stabilized by three‐coordinated nitrogen atoms and one‐sulfur atom (Fe‐N3S‐C). It was further found that the replacement of one N atom with S atom in the classical Fe‐N4‐C active center could induce an asymmetric charge distribution over N atoms surrounding the Fe reactive center to accelerate proton spillover for a rapid formation of the OOH* intermediate, thus speeding up the whole reaction kinetics of oxygen reduction for H2O2 electrosynthesis. [ABSTRACT FROM AUTHOR]

The development of precious‐metal alternative electrocatalysts for oxygen reduction reaction (ORR) is highly desired for a variety of fuel cells, and single atom catalysts (SACs) have been envisaged to be the promising choice. However, there remains challenges in the synthesis of high metal loading SACs (>5 wt.%), thus limiting their electrocatalytic performance. Herein, a facile self‐sacrificing template strategy is developed for fabricating Co single atoms along with Co atomic clusters co‐anchored on porous‐rich nitrogen‐doped graphene (Co SAs/AC@NG), which is implemented by the pyrolysis of dicyandiamide with the formation of layered g‐C3N4 as sacrificed templates, providing rich anchoring sites to achieve high Co loading up to 14.0 wt.% in Co SAs/AC@NG. Experiments combined with density functional theory calculations reveal that the co‐existence of Co single atoms and clusters with underlying nitrogen doped carbon in the optimized Co40SAs/AC@NG synergistically contributes to the enhanced electrocatalysis for ORR, which outperforms the state‐of‐the‐art Pt/C catalysts with presenting a high half‐wave potential (E1/2 = 0.890 V) and robust long‐term stability. Moreover, the Co40SAs/AC@NG presents excellent performance in Zn–air battery with a high‐peak power density (221 mW cm−2) and strong cycling stability, demonstrating great potential for energy storage applications. [ABSTRACT FROM AUTHOR]

Glycerol, as the major by‐product of biodiesel, can be oxidized into diverse value‐added chemical products via either traditional chemical methods or electrochemical routes. Electrocatalytic glycerol oxidation reaction (GOR) driven by renewable‐derived electricity (e.g., wind and solar) is a promising pathway for fine chemicals production. In an electrochemical cell, GOR can be coupled with various cathodic reactions, including hydrogen evolution reaction (HER), CO2 reduction reaction (CO2RR), and oxygen reduction reaction (ORR); in this manner, different benefits of either energy effectiveness or additional value‐added products can be obtained depending on the cathode reduction reaction selected. Comprehensively understanding of electrocatalytic GOR and the associated processes is of great significance to promote its industrial application. Herein, recent progress of GOR is focused on. The background of biomass‐derived glycerol valorization to energy and value‐added chemicals as well as the electrochemical conversion techniques via GOR is introduced. Then, the electrocatalytic reaction pathways, the potential application of GOR, and the measurement method for products are also discussed and summarized. Special emphasis is put on the design and the development of high‐selectivity and high‐activity electrocatalysts for GOR. Finally, the challenges and the future prospects in the fields of GOR are highlighted. [ABSTRACT FROM AUTHOR]

We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen‐rich metal–organic framework (Zn‐MOF‐74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2RR. The NPC exhibits superior CO2RR activity with a small onset potential of −0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at −0.55 V vs. RHE, one of the highest values among NPC‐based CO2RR electrocatalysts. This work advances an effective and facile way towards highly active and cost‐effective alternatives to noble‐metal CO2RR electrocatalysts for practical applications. [ABSTRACT FROM AUTHOR]

Developing efficient and low‐cost catalysts with excellent catalytic activities for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of significance for large‐scale commercial applications in rechargeable Zn−air batteries and fuel cells. Herein, we develop a simple, mild and efficient method to synthesize a hybrid of N‐doped carbon nanosheets encapsulating cobalt nanoparticles (Co@NCNSs), which shows favorable catalytic properties toward both ORR and OER with high activity and good stability. The optimized hybrids (Co@NCNSs‐900) exhibit an onset potential of 0.95 V vs. reversible hydrogen electrode (RHE) and a half‐wave potential of 0.85 V vs. RHE for the ORR, and an onset potential of 1.51 V vs. RHE, a potential of 1.59 V vs. RHE at 10 mA cm−2 for the OER, as well as an oxygen electrode activity parameter (ΔE) of 0.802 V in alkaline electrolyte. Moreover, the Zn−air battery with the Co@NCNSs‐900 as the cathode catalyst outperforms that with the commercial Pt/C as cathode catalyst in terms of the maximum power density and stability, showing great prospects in renewable energy applications. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR), as one of the most critical but promising reactions for energy conversion, has attracted increasing research interest. Recent reports have evidenced that carbonization of heteroatoms doped porous organic polymers (POPs) is an effective approach toward highly efficient ORR electrocatalysts. We herein report a versatile ternary copolymerization strategy to synthesize stable POPs gel with tunable doping of heteroatoms (N, S, F) and Fe species, leading to significant enhancement in surface area and porosity. Carbonization of these POPs afford efficient ORR electrocatalyst with optimized composition, hierarchical porous structure and prominent catalytic activities in both alkaline and neutral conditions. The optimized catalyst (TF‐C‐900) exhibited an onset potential (Eonset) of 1.01 V and half‐wave potential (E1/2) of 0.88 V in 0.1 M KOH solution. These performance metrics are even comparable to those of the Pt/C (0.99 and 0.85). In addition, the TF‐C‐900 also showed superior stability and advantage of methanol tolerance, enabling them to be a competitive cathode electrocatalysts for alkaline fuel cell. Porous organic polymer gels synthesized via ternary polymerization were used to fabricate heteroatom‐doped catalysts for the oxygen reduction reaction and as cathode material in Zn‐air batteries. The porous structure showed prominent catalytic activity under both alkaline and neutral conditions, superior stability and advantage of methanol tolerance, enabling them to be a competitive cathode electrocatalysts for alkaline fuel cell. [ABSTRACT FROM AUTHOR]

Developing high-active, good-stable, and cost-effective electrocatalyst for oxygen reduction reaction (ORR) in all-pH medium is highly desired for the application of various fuel cell systems. Here, a network architecture hybrid with porous nitrogen-doped graphene encapsulated β-FeOOH nanoparticals (β-FeOOH/PNGNs) as ORR electrocatalyst, which exhibits remarkable enhancement ORR performance in terms of activity and stability in pHuniversal medium is reported. Systematic characterization combining with X-ray absorption fine structure analysis and the first principles simulations reveal that the as-formed surface FeO6 active sites that induced by a mass of Fe vacancies in β-FeOOH/PNGNs can significantly lower the thermodynamic barrier of the total reaction, and hence contribute to a remarkable enhancement in ORR activity. [ABSTRACT FROM AUTHOR]

It is of increasing importance to explore new low-cost and high-activity electrocatalysts for oxygen reduction reaction (ORR), which have had a substantial impact across a diverse range of energy conversion system, including various fuel cell and metal-air batteries. Although engineering carbon nanostructures have been widely explored as a candidate class of Pt-based ORR electrocatalysts owing to their proved high activity, outstanding stability, and ease of use, there still remains a daunting challenge to develop high activity metal-free electrocatalysts in pH-universal electrolyte system. Here, a reliable and controllable route amenable to prepare nitrogen-doped porous carbon (NPC) with high yields and exceptional quality is described. The as-prepared NPC shows advantages of high activity, high durability, and methanol-tolerant as an efficient pH-universal electrocatalyst for ORR, showing comparable or even better activity as compared with the commercial Pt/C catalysts not only in alkaline media but also in acidic and neutral electrolyte. Systematic electrochemical studies, combining with density functional theory calculation, demonstrate the unique nitrogen-doping species and favorable pores in the as-designed NPC synergistically contribute to the significantly improved catalytic activity in pH-universal medium. The present work potentially presents an important breakthrough in developing ORR electrocatalysts for various fuel cells. [ABSTRACT FROM AUTHOR]

A simple pyrolysis route has been developed for fabrication of nitrogen-doped carbon networks (N-C net) that not only features a large number of mesoporous structures, but also holds high specific surface area and excellent conductivity. The as-developed N-C net performs impressively toward electrocatalysis of oxygen reduction reaction (ORR) and CO 2 reduction reaction (CO 2 RR). For ORR in alkaline electrolyte, the N-C net manifests an initial potential of 0.95 V and half-wave potential of 0.86 V that are comparable to the benchmarked Pt/C catalysts. While for CO 2 RR, the N-C net shows a high selectivity for CO production with Faraday efficiency (FE) of as high as 95% and long-term stability. We further demonstrate the potential application of N-C net in electrochemical devices of zinc-air batteries (ZABs) and microbial CO 2 electrolysis cell (MEC), the former is capable of releasing a maximum power density of 141 mW cm-2, while the later shows capability for efficiently converting CO 2 into CO with the assistance of external voltage. We thus propose and set up an integrated proof-of-concept electrochemical device with ZABs driving MEC that can implement the feasibility of self-powered conversion of CO 2 to value-added CO. [Display omitted] • The N-doped carbon networks prepared by one-pot pyrolyzing ZIF-8 exhibited excellent electrocatalytic properties toward oxygen reaction reduction and CO 2 reduction. • Catalyzed by the cathodic bifunctional N-doped carbon networks, the Zn-air batteries and microbial CO 2 electrolysis cell with favorable performance were assembled in this work. • A coupled electrochemical device with ZABs driving MEC was firstly proposed and achieved self-powered conversion of CO 2 to value-added CO. [ABSTRACT FROM AUTHOR]

A facile recipe has been developed to prepare three-dimensional nanoarchitectures of nitrogen-doped graphene loading Co nanoparticle hybrids (Co/NG). The hybrids show an outstanding electrocatalytic activity for glucose oxidation reaction (GOR) and oxygen reduction reaction (ORR), and thus can be used as electrode materials of a nonenzymatic and precious-metal-free glucose fuel cell (GFC). [ABSTRACT FROM AUTHOR]

A novel hybrid electrocatalyst consisting of nitrogen-doped graphene/cobalt-embedded porous carbon polyhedron (N/Co-doped PCP//NRGO) is prepared through simple pyrolysis of graphene oxide-supported cobalt-based zeolitic imidazolate-frameworks. Remarkable features of the porous carbon structure, N/Co-doping effect, introduction of NRGO, and good contact between N/Co-doped PCP and NRGO result in a high catalytic efficiency. The hybrid shows excellent electrocatalytic activities and kinetics for oxygen reduction reaction in basic media, which compares favorably with those of the Pt/C catalyst, together with superior durability, a four-electron pathway, and excellent methanol tolerance. The hybrid also exhibits superior performance for hydrogen evolution reaction, offering a low onset overpotential of 58 mV and a stable current density of 10 mA cm−2 at 229 mV in acid media, as well as good catalytic performance for oxygen evolution reaction (a small overpotential of 1.66 V for 10 mA cm−2 current density). The dual-active-site mechanism originating from synergic effects between N/Co-doped PCP and NRGO is responsible for the excellent performance of the hybrid. This development offers an attractive catalyst material for large-scale fuel cells and water splitting technologies. [ABSTRACT FROM AUTHOR]

Optimized electrocatalyst that hybrids with carbon coating FeCoP x nanoparticles possesses catalytic activity toward ORR, OER and HER. Furthermore, through the design of alkali-acid electrolyzer and device integration, for the very first time, a single Zinc-air battery enable to drive an alkali-acid electrolyzer for producing hydrogen and oxygen. [Display omitted] • A one-pot scalable pyrolysis strategy to fabricate a tri-functional electrocatalyst. • High catalytic activity toward ORR&OER in alkaline and HER in acidic media. • The Zn-air battery can run stably for 1500 cycles. • An alkali-acid electrolyzer only requires 0.99 V to release an electrolysis current density of 10 mA cm−2. • A single self-made Zinc-air battery can drive an alkali-acid electrolyzer to produce hydrogen. Developing handy synthesis routes to fabricate low-cost, high-activity, and multifunctional electrocatalysts for a variety of electrochemical reactions is highly desirable so as to achieve the goal that one catalyst can be used for integrated electrolysis devices, thus greatly simplifying the electrocatalyst system processing. Here, we report a one-pot scalable pyrolysis strategy to fabricate a tri-functional electrocatalyst, i.e. , hybrids with carbon coating FeCoP x nanoparticles, which shows favorable electrocatalytic properties toward oxygen reduction reaction, oxygen evolution reaction in alkaline solution, and hydrogen evolution reaction in acidic condition. The new synthesis routes enable us to readily develop an integrated device with a Zn-air battery driving an alkali-acid electrolyzer by just using one catalyst. The present work may shed light on the practical viability of the development of multifunctional electrocatalysts for integrated devices applications. [ABSTRACT FROM AUTHOR]

Potassium-Ion Hybrid Capacitors: Fast Redox Kinetics in Bi-Heteroatom Doped 3D Porous Carbon Nanosheets for High-Performance Hybrid Potassium-Ion Battery Capacitors (Adv. Keywords: fast kinetics; porous carbon nanosheets; potassium-ion hybrid capacitors; sulfur and nitrogen codoped Fast kinetics, porous carbon nanosheets, potassium-ion hybrid capacitors, sulfur and nitrogen codoped. [Extracted from the article]

Potassium‐ion hybrid capacitors (PIHCs) hold the advantages of high‐energy density of batteries and high‐power output of supercapacitors and thus present great promise for the next generation of electrochemical energy storage devices. One of the most crucial tasks for developing a high‐performance PIHCs is to explore a favorable anode material with capability to balance the kinetics mismatch between battery‐type anodes and capacitor‐type cathode. Herein, a reliable route for fabricating sulfur and nitrogen codoped 3D porous carbon nanosheets (S‐N‐PCNs) is reported. Systematic characterizations coupled with kinetics analysis indicate that the doped heteroatoms of sulfur and nitrogen and the amplified graphite interlayer can provide ample structural defects and redox active sites that are beneficial for improving pseudocapacitive activity, enabling fast kinetics toward efficient potassium‐ion storage. The S‐N‐PCNs are demonstrated to exhibit superior potassium storage capability with a high capacity of 107 mAh g−1 at 20 A g−1 and long cycle stability. The as‐developed PIHCs present impressive electrochemical performance with an operating voltage as high as 4.0 V, an energy density of 187 Wh kg−1, a power density of 5136 W kg−1, and a capacity retention of 86.4% after 3000 cycles. [ABSTRACT FROM AUTHOR]

On page 872 novel nitrogen‐doped graphene/cobalt‐embedded porous carbon polyhedron hybrid electrocatalyst is obtained by Z. H. Wen, J. H. Chen, and co‐workers through a simple strategy. Benefitting from well defined structural features including excellent porous carbon structure, N/Co‐doping effect, introduction of NRGO, and good contact between N/Co‐doped PCP and NRGO sheets, the hybrid exhibits excellent tri‐functional catalytic activities for ORR, HER, and OER with long‐term stability in both acid and basic media. [ABSTRACT FROM AUTHOR]

Transition metal carbide catalysts are the alternative products of traditional noble metal Pt/C in oxygen reduction reaction (ORR). Oleic acid-coated iron oxide nanoparticles (F 3 O 4 @OA) was prepared by pyrolysis, assembled with reduced graphene oxide (rGO), and carbonized at 800 °C to obtain N doped iron carbide nanoparticles supported rGO (N–Fe 3 C/rGO). The particle size of nanocrystals increases significantly with the graphene loading risen can be seen in the transmission electron microscope (TEM) image which roughly distributed around 40 nm. The linear scanning voltammetry (LSV) curve shows the material has an ORR performance equivalent to Pt/C in alkaline media. • Controllable supported Fe 3 C nanocrystals on rGO. • Enhanced electrochemical performance by proportion Fe 3 C on rGO. • Remarkably enhanced ORR performance. [ABSTRACT FROM AUTHOR]

Highly electrocatalytic activity and strong stability towards both oxygen evolution (OER) and oxygen reduction reaction (ORR) have been regarded as the critical factors in widespread application for the renewable energy technologies. It still remains a huge challenge for developing bifunctional catalysts with low cost, efficiently electrocatalytic activity and strong stability. In this paper, FeCo alloy nanoparticles embedded in nitrogen-doped carbon are synthesized through a simple thermal decomposition of Co-Fe Prussian Blue Analogue (Co-Fe PBA) in Ar atmosphere, during which the organic ligand of CN − in Co-Fe PBA provides both carbon and nitrogen sources for forming nitrogen-doped carbon and FeCo alloy nanoparticles were formed, and thus producing a core-shell structure (FeCo@NC). According to a set of electrochemical tests, the obtained FeCo@NC can function as a Janus to drive OER and ORR with desirable activities and stabilities in alkaline media. Specifically, the FeCo@NC presents an onset-potential of 1.45 V, a potential of 1.49 V at 10 mA cm −2 , a Tafel slope of 62 mV dec −1 as OER catalyst, and an onset potential of 0.94 V, a half-wave potential of 0.8 V as ORR catalyst. The performance is comparable to those of precious metal based electrocatalysts, making it possible for potential application in the renewable energy devices, especially Zn-air battery. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) is a device that uses microorganisms as biocatalysts to directly convert the chemical energy of waste organic into electrical energy. The sluggish kinetics and the high cost of oxygen reduction reaction (ORR) are the major factors hindering the development of MFCs, especially in neutral electrolyte that is widely used in common MFCs. Therefore, it is highly desirable either to explore cheap cathode ORR catalysts with high catalytic activity and stability, or to develop newly MFCs system that can significantly enhance cathode kinetic. In this study, we develop a metal-free N/B-co-doped carbon-based catalyst (denoted as PANI/B-8) by pyrolysis of mixtures of polyaniline and boric acid, which show remarkably improved kinetic and activity toward ORR in alkaline electrolyte relative to neutral electrolyte, inspiring us to develop an asymmetric neutral-alkaline microbial fuel cell (ANA-MFCs) with microbial as neutral anode catalysts and PANI/B-8 as alkaline cathode catalysts, between the two chambers are separated by a proton exchange membrane (PEM) to prevent mixing of anolyte and catholyte while to ensure ion conductivity. The present ANA-MFCs notably deliver an output power density twice higher than that of the symmetric MFCs, thanks to the remarkably enhanced ORR kinetic in alkaline cathode reaction. The asymmetric neutral-alkaline microbial fuel cell with N/B Co-doped carbon exhibits prominent battery performance compared to conventional neutral-neutral device. And it delivers a current value twice higher than that of the symmetric device, thanks to the remarkably enhanced ORR kinetic in alkaline cathode reaction. [Display omitted] [ABSTRACT FROM AUTHOR]

• Ni@NiO-Cu@CuO/NCS is prepared from MOF material via direct calcination process. • Material favors to human urine urea oxidation and groundwater NO 3 − reduction. • Presence of M2+/M3+ redox couple offers better bifunctional catalytic activity. • Substitution of ORR with NRR launches a new branch of fuel cell named UNFC. Though direct urea fuel cells (DUFCs) show promising potential for green energy generation, the practical feasibility of its on-site installation is yet encumbered by the sluggish electrokinetics and low-value product (H 2 O) of oxygen reduction reaction (ORR). We here report the design and synthesis of a bifunctional hybrid electrocatalyst of nitrogen-doped carbon sheets supporting Ni@NiO-Cu@CuO composites (Ni@NiO-Cu@CuO/NCS) via direct calcination of Ni- and Cu-containing metal organic frameworks (MOFs). The as-derived nanohybrid shows impressively high catalytic performance towards urea oxidation reaction (UOR) in alkali and nitrate reduction reaction (NRR) in acidic electrolyte, which inspire us to set up a urea-nitrate fuel cell (UNFC). Owing to the excellent electrochemical characteristics behaviour of prepared nanostructures, the fabricated UNFC simultaneously exhibits improved fuel cell performance of 22.55 ± 2.3 mW cm−2 and degrade the urine and nitrate at the anode and cathode, respectively. The presented innovative electrochemical device may open up a prime step for the development of renewable UNFC for simultaneous green energy generation and N-containing waste removal. [ABSTRACT FROM AUTHOR]

It presents the scalable salt-templated synthesis of two-dimensional porous fluorine-doped carbon (FC) nanosheets with the high active sites and larger special surface area, which shows impressive oxygen reduction reaction (ORR) activities. The synergistic effect of fluoride doping and defects provided more density of active sites in carbon material. It may open up a promising avenue for developing electrocatalysts with high catalytic activity and high stability for electrolyzed application. • Two-dimensional porous fluorine-doped carbon (FC) nanosheets. • Long-term durability and the large active surface area. • Remarkably enhanced oxygen electrocatalytic performance. We present the scalable salt-templated synthesis of two-dimensional porous fluorine-doped carbon (FC) nanosheets. Due to the larger special surface area (1031 m2 g−1) and high active sites, FC-900 (pyrolyzed at 900 °C) shows impressive oxygen reduction reaction (ORR). The synergistic effect of fluoride doping and defects provides richer density of active sites in these nanosheets. When the samples are further calcined at 900 °C for different hours, the ORR activity of the resulting samples shows a little improvement, indicating the influence of the defects on the ORR performance is much inferior to the doped fluorine. The formation of FC structures is beneficial to the ORR activity, and supported by First-principles density functional theory. The results reveal F dopants and defects important role in efficient ORR electrocatalysis owing to the synergistic effect, which is important for comprehending the origin of ORR, and it is also strong evidence to search advanced carbon-based catalysts. [ABSTRACT FROM AUTHOR]

The electrocatalytic oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO 2 RR) are considered as major strides for the development of a global-scale sustainable energy system, owing to their potential in neutralizing carbon emissions, generating value-added product, and delivering clean energy. However, the practicability of ORR and CO 2 RR is hampered by the sluggish kinetics and instability of the catalyst materials, calling for thirst for exploring efficient and stable electrocatalyst. With this concern, we herein report a hybrid (c-CoACC/CNTs) with carbon nanotubes (CNTs) decorating cubic cobalt amide cyanide complex (c-CoACC), which is synthesized by using molten salt (MS) assisted method and exhibits highly crystalline and thermally stable features. The c-CoACC/CNTs exhibit profound ORR activity with the onset and half-wave potential (E 1/2) of 0.972 and 0.87 V in alkaline conditions, respectively. The practical application of c-CoACC/CNTs as ORR catalysts has been verified in a home-made zinc-air battery, which is capable of releasing a maximum power density of 188 mW cm−2 in comparison with 175 mW cm−2 in the Pt/C based zinc-air battery. Furthermore, the c-CoACC/CNTs exhibits desirable electrocatalytic properties toward CO 2 -to-CO conversion in 0.5 M KHCO 3 with a tunable production ratio between CO and H 2 , yielding a maximum Faraday efficiency of 83.8% at −0.78 V vs. RHE. The attractive electrocatalytic properties in the c-CoACC/CNTs can be attributed to the improved electroactive sites relative to individual c-CoACC and CNT, reduced diffusion resistance, and enhanced three-phase boundaries. Notably, the c-CoACC/CNTs perform encouraging stability in the catalysis of ORR and CO 2 RR under various electrochemical regimes and conditions, directing a viable path for a future global-scale sustainable energy system. [ABSTRACT FROM AUTHOR]