Developing active, robust, and nonprecious electrocatalysts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) is highly crucial and challenging. In this work, a facile strategy is developed for scalable fabrication of dicobalt phosphide (Co2P)–cobalt nitride (CoN) core–shell nanoparticles with double active sites encapsulated in nitrogen‐doped carbon nanotubes (Co2P/CoN‐in‐NCNTs) by straight forward pyrolysis method. Both density functional theory calculation and experimental results reveal that pyrrole nitrogen coupled with Co2P is the most active one for HER, while Co–N–C active sites existing on the interfaces between CoN and N‐doped carbon shells are responsible for the ORR and OER activity in this catalyst. Furthermore, liquid‐state and all‐solid‐state Zn–air batteries are equipped. Co2P/CoN‐in‐NCNTs show high power density as high as 194.6 mW cm−2, high gravimetric energy density of 844.5 W h kg−1, very low charge–discharge polarization, and excellent reversibility of 96 h at 5 mA cm−2 in liquid system. Moreover, the Co2P/CoN‐in‐NCNTs profiles confirm excellent activity for water splitting.

Structural and compositional engineering of atomic-scaled metal-N-C catalysts is important yet challenging in boosting their performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Here, boron (B)-doped Co-N-C active sites confined in hierarchical porous carbon sheets (denoted as Co-N,B-CSs) were obtained by a soft template self-assembly pyrolysis method. Significantly, the introduced B element gives an electron-deficient site that can activate the electron transfer around the Co-N-C sites, strengthen the interaction with oxygenated species, and thus accelerate reaction kinetics in the 4e processed ORR and OER. As a result, the catalyst showed Pt-like ORR performance with a half-wave potential (E) of 0.83 V versus (vs) RHE, a limiting current density of about 5.66 mA cm, and higher durability (almost no decay after 5000 cycles) than Pt/C catalysts. Moreover, a rechargeable Zn-air battery device comprising this Co-N,B-CSs catalyst shows superior performance with an open-circuit potential of ∼1.4 V, a peak power density of ∼100.4 mW cm, as well as excellent durability (128 cycles for 14 h of operation). DFT calculations further demonstrated that the coupling of Co-N active sites with B atoms prefers to adsorb an O molecule in side-on mode and accelerates ORR kinetics.

Although great attention has been paid to wearable electronic devices in recent years, flexible lightweight batteries or supercapacitors with high performance are still not readily available due to the limitations of the flexible electrode inventory. In this work, highly flexible, bendable and conductive rGO-PEDOT/PSS films were prepared using a simple bar-coating method. The assembled device using rGO-PEDOT/PSS electrode could be bent and rolled up without any decrease in electrochemical performance. A relatively high areal capacitance of 448 mF cm−2 was achieved at a scan rate of 10 mV s−1 using the composite electrode with a high mass loading (8.49 mg cm−2), indicating the potential to be used in practical applications. To demonstrate this applicability, a roll-up supercapacitor device was constructed, which illustrated the operation of a green LED light for 20 seconds when fully charged.

During the preparation of atomically dispersed Fe–N–C catalysts, it is difficult to avoid the formation of iron‐carbide‐containing iron clusters (“FexC/Fe”), along with the desired carbon matrix containing dispersed FeNx sites. As a result, an uncertain amount of the oxygen reduction reaction (ORR) occurs, making it difficult to maximize the catalytic efficiency. Herein, sulfuration is used to boost the activity of FexC/Fe, forming an improved system, “FeNC–S–FexC/Fe”, for catalysis involving oxygen. Various spectroscopic techniques are used to define the composition of the active sites, which include Fe–S bonds at the interface of the now‐S‐doped carbon matrix and the FexC/Fe clusters. In addition to outstanding activity in basic media, FeNC–S–FexC/Fe exhibits improved ORR activity and durability in acidic media; its half‐wave potential of 0.821 V outperforms the commercial Pt/C catalyst (20%), and its activity does not decay even after 10 000 cycles. Interestingly, the catalytic activity for the oxygen evolution reaction (OER) simultaneously improves. Thus, FeNC–S–FexC/Fe can be used as a high‐performance bifunctional catalyst in Zn–air batteries. Theoretical calculations and control experiments show that the original FeNx active centers are enhanced by the FexC/Fe clusters and the Fe–S and C–S–C bonds.

Molybdenum disulfide (MoS 2 )h as been widely studied as ap otential earth-abundant electrocatalyst for the hydrogen-evolution reaction (HER). Defect engineering and heteroelemental doping are effective methods to enhance the catalytic activity in the HER, so exploring an efficient route to simultaneously achieve in-plane vacancy engineering and elemental doping of MoS 2 is necessary.I nt his study,Z inc, al ow-cost and moderately active metal, has been used to realizethis strategy by generation of sulfur vacancies and zinc doping on MoS 2 in one step.D ensity functional theory calculations reveal that the zinc atoms not only lower the formation energy of Svacancies,but also help to decrease DG H of S-vacancy sites near the Zn atoms.A ta no ptimal zincreduced MoS 2 (Zn@MoS 2 )example,the activated basal planes contribute to the HER activity with an overpotential of À194 mV at 10 mA cm À2 and al ow Tafel slope of 78 mV/dec.