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Hydrogen peroxide production through the electrochemical two-electron oxygen reduction presents a compelling alternative to the anthraquinone process due to the cheap starting materials and low operating temperature and pressure. Transition metal species featuring with multi-active sites, offer high electrochemical activity and selectivity. MXenes, distinguished by excellent electrical conductivity and the two-dimensional structure facilitating smooth ion transportation, further enhance the prospects of this production approach. In this study, three Mo-based MXenes were synthesized: Mo 2 TiC 2 F x , Mo 2 Ti 2 C 3 F x and Mo 2 CF x. Among these, Mo 2 TiC 2 F x emerged as the most promising catalyst for 2e−ORR, achieving a remarkable H 2 O 2 yield of up to 0.54 mol·g cat −1·h−1. Moreover, it also exhibits a high H 2 O 2 selectivity ranging from 81.3 % at 0.2 V to 94.1 % at 0.6 V vs. RHE, coupled with an impressive faradaic efficiency of 76.4 % at 0.4 V using H-cell. Further analysis indicates that the superior 2e−ORR performance can be attributed to the presence of metallic Mo on the surface of Mo 2 TiC 2 F x. [ABSTRACT FROM AUTHOR]

Developing low cost and high performance catalyst for oxygen evolution reaction is the key to evolving sustainable energy. We synthesize a well-designed architecture comprising of lead grid wrapping by perpendicularly grown lead oxide flakes. Oxygen evolution activities are largely improved after carving the lead foil into lead grid and further enhanced by a secondary structure of lead oxide flakes, with a negatively-shift of onset potential (~65 mV) and smaller overpotential to deliver a current density of 80 mA cm−2 (~350 mV). The electrode is demonstrated to be highly stable under acidic water at 60 °C for 8 h. We believe the excellence in electrochemistry is attributed to increased active sites, good electrical conductivity and sufficient porosity to facilitate reactant water flow and high gas permeability especially at high current densities. [Display omitted] • Electrode in this work is combined of laser cutting and hydrothermal technology. • OER of lead foils are improved after gridding and covering lead oxide flakes. • The lead oxide/lead grid electrode is highly stable under acidic water at 60 °C. • Positive effects are due to increased active sites, good conductivity and porosity. [ABSTRACT FROM AUTHOR]

In this paper, Ag–ZnO and Ag–MoS 2 –ZnO were successfully synthesized by hydrothermal method. The synthesized samples' physical properties were characterized by FESEM, XRD, TEM, EDS and BET. The catalytic activity of the synthesized samples for the hydrogen evolution reaction was investigated by an electrochemical workstation in 0.1 M KOH. XRD results indicate that 5% Ag-5% MoS 2 –ZnO with good crystallinity and purity is synthesized. According to the SEM results, Ag and ZnO are evenly distributed on the MoS 2 nanosheets in the 5% Ag-5% MoS 2 –ZnO. LSV results show that adding Ag or MoS 2 to ZnO can improve its catalytic activity. 5% Ag - ZnO had the best hydrogen evolution activity, and the overpotential was 568 mV. The catalytic activity of ZnO doped with Ag and MoS 2 is higher than ZnO doped with Ag or MoS 2 alone for hydrogen evolution reaction, this is mainly due to the synergy of heterojunction and Ag. [ABSTRACT FROM AUTHOR]

In the paper, Pd/TiO 2 was successfully prepared by anodic oxidation and electrodeposition. When the time of depositing Pd is 15 min and 5 min, the electrocatalyst is marked as 15 min Pd/TiO 2 and 5 min Pd/TiO 2 respectively. The physical properties of Pd/TiO 2 were characterized by XRD (X-ray diffraction), EDS (energy dispersive spectroscopy), SEM (scanning electron microscope) and XPS (X-ray photoelectron spectroscopy). The catalytic activity of Pd/TiO 2 for hydrogen evolution reaction (HER) in 1 M KOH solution was characterized by the electrochemical workstation. XRD results showed that Pd/TiO 2 was successfully synthesized; the EDS and XPS results confirmed the above results. SEM results show that Pd nanoparticles are uniformly distributed on the surface of TiO 2 nanotube arrays. The electrochemical results show that Pd/TiO 2 has better catalytic activity than TiO 2. Compared with 5 min Pd/TiO 2 and TiO 2 -2h, the overpotential of 15 min Pd/TiO 2 is positively shifted by 98 mV and 588 mV, respectively. The 15 min Pd/TiO 2 still has good catalytic activity after 2000 CV cycles. The catalytic performance of all catalysts in 1 M KOH is better than that in 1 M Na 2 SO 4. Image 1 • Pd/TiO 2 was successfully synthesized by anodic oxidation and electrodeposition. • The overpotential of 15 min Pd/TiO 2 is 149 mV in 1 M KOH. • Pd/TiO 2 showed good stability in 1 M KOH for hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

The production of H 2 O 2 by oxygen reduction reaction (ORR) is low energy consumption and environmentally friendly. Pd/C is an effective electrocatalyst for oxygen reduction, while its selectivity is low due to a tendentious four-electron pathway ORR process. The limited reserves of palladium and inevitable corrosion issue of carbon support add extra obstacles toward practical application. In this work, Pd nanoparticles with 3–5 nm were synthesized on MXene sheets. Results indicated that Pd/MXene exhibited 3.5∼4.2 times ring current than Pd/C and much higher H 2 O 2 selectivity. The H 2 O 2 yield of Pd/MXene was measured to be 1.43 mol g−1 h−1. The excellence in electrochemistry was from the synergistic effect of Pd and MXene. The existence of MXene increases metallic Pd on the surface. This study on MXenes as supports of Pd nanoparticles for two-electron oxygen reduction provides extensive reference significance to H 2 O 2 generation. [ABSTRACT FROM AUTHOR]

• Three-metal lanthanide MOF was electrochemically constructed for the first time. • A high specific capacitance of 965 F g−1 was achieved at 5 A g−1. • A superior cycling performance of 94.5% was observed after 6000 cycles at 5 A g−1. In this work, a novel mixed-lanthanide metal–organic framework (ML-MOF, ML = La3+, Gd3+ and Tm3+) is synthesized for the first time through a simple reductive electrodeposition procedure onto nickel foam and its charge storage ability is investigated. The as-prepared ML-MOF is characterized through FE-SEM, EDS, XRD, FT-IR and TGA analyses. The results of these analyses confirmed deposition of the crystalline well-defined rod-like ML-MOF with composition of {La 2 Gd 0.5 Tm 0.5 BTC]. x H 2 O} n onto Ni foam. The fabricated ML-MOF/NF electrode delivered specific capacity values of 965F g−1 and 594 F g−1 at 5 and 50 A g−1, and capacity retention of 94.5% after 6000 cycles at high current load of 5 A g−1, which confirmed its superior rate ability and excellent cycling performance. Based on the results, the applied electrochemical strategy is introduced as a simple facile way for synthesis of various ML-MOF materials for different electrochemical applications. [ABSTRACT FROM AUTHOR]

The key to synthesis highly efficient MoS 2 based electrocatalyst for hydrogen evolution reaction (HER) is to construct a reasonable composite system structure to improve the stability, reduce the aggregation and improve the intrinsic poor conductivity. In this paper, MoS₂ composite of erbium-based metal-organic framework (noted as Er-MOF/MoS 2) were synthesized by hydrothermal method. The morphology and structure of the synthesized samples were characterized by powder X-ray diffraction (XRD), field emission electron microscopy (FESEM), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), and the electrocatalytic performances were tested by linear sweep voltammograms (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), i-t. On the basis of the experiment, Er-MOF/MoS 2 shows improved conductivity and more exposed active sites, exhibiting excellent HER activity in acidic media, with only 234 mV overpotential to achieve 10 mA cm−2, and a Tafel slope of 54.3 mV dec−1. This strategy of porous structure of MoS 2 composite rare earth metal organic framework materials provides a novel and effective solution for preparing high performance MoS 2 based electrocatalyst. • Er-MOF and Er-MOF/MoS 2 were prepared by hydrothermal method. • Er-MOF as supports improved the catalytic activity and more exposed active sites of MoS 2 in acidic media. • Er-MOF/MoS 2 shows excellent long-term durability. [ABSTRACT FROM AUTHOR]

Weak electrical conduction impedes the application of Metal-organic framework (MOF) in electrochemistry. In this work, palladium-based MOF (Pd/MOF) is synthesized via i) simple solvothermal process and ii) direct chemical reduction method. N 2 adsorption-desorption isotherms and thermogravimetric analyzer show that MOF have large specific surface area and good thermal stability. The synthesized materials were tested in acidic condition for hydrogen evolution reaction (HER). Electrochemical test results show that Pd/MOF with tafel slope of 85 mV·dec−1, onset overpotential of 105 mV and ideal stability has better performance than bulk MOF for HER. The enhanced performance can be ascribed to the large porosity and specific surface of MOF, and the synergistic effect between Pd and MOF toward H 2 production. Image 1 • Pd enhanced MOFs has been prepared with a simple two-step method. • Pd/MOFs material has good electrocatalytic activity and stability for HER. • Pd/MOFs are spherical with a radius of 2.2 μm. [ABSTRACT FROM AUTHOR]