Insightful understanding of three-phase interface behaviors in 1T-2H MoS2/CFP electrode for hydrogen evolution improvement

An exploration of the solution of direct methanol fuel cell cost effectiveness

The work in this paper incorporated printed circuit board (PCB) technology into micro-direct methanol fuel cells (µDMFCs) and conjectured and verified the performance degradation factors of PCB current collectors in µDMFCs by testing different designed configuration µDMFCs. The experiment results showed that all kinds of PCB coating can benefit from the porous stainless-steel plates covering to a great extent. At the end of 48 h discharging, µDMFCs with porous stainless-steel plates between MEA and PCB coating achieved higher performance than those of the direct contacting series. It can be inferred from various types of experimental data that because of stainless-steel porous plate isolating, the impact of corrosion on the surface of the PCB electrode plate was reduced to a certain extent. The corrosion of the electrode plate was slowed down in the µDMFC discharging as a result of the passivation behavior on the iron surface and a decrease in corrosion current. Consequently, the attenuation of the PCB performance was delayed. The conclusion of this work explores a practical direction to enhance the cost-effectiveness of fuel cells, promoting the large-scale application of DMFCs in the future.

Subtle 2D/2D MXene-Based Heterostructures for High-Performance Electrocatalytic Water Splitting

Developing efficient electrocatalysts is significant for the commercial application of electrocatalytic water splitting. 2D materials have presented great prospects in electrocatalysis for their high surface-to-volume ratio and tunable electronic properties. Particularly, MXene emerges as one of the most promising candidates for electrocatalysts, exhibiting unique advantages of hydrophilicity, outstanding conductivity, and exceptional stability. However, it suffers from lacking catalytic active sites, poor oxidation resistance, and easy stacking, leading to a significant suppression of the catalytic performance. Combining MXene with other 2D materials is an effective way to tackle the aforementioned drawbacks. In this review, the focus is on the accurate synthesis of 2D/2D MXene-based catalysts toward electrocatalytic water splitting. First, the mechanisms of electrocatalytic water splitting and the relative properties and preparation methods of MXenes are introduced to offer the basis for accurate synthesis of 2D/2D MXene-based catalysts. Then, the accurate synthesis methods for various categories of 2D/2D MXene-based catalysts, such as wet-chemical, phase-transformation, electrodeposition, etc., are systematically elaborated. Furthermore, in-depth investigations are conducted into the internal interactions and structure-performance relationship of 2D/2D MXene-based catalysts. Finally, the current challenges and future opportunities are proposed for the development of 2D/2D MXene-based catalysts, aiming to enlighten these promising nanomaterials for electrocatalytic water splitting.

Ultrafast synthesis of halogen-doped Ru-based electrocatalysts with electronic regulation for hydrogen generation in acidic and alkaline media

Developing a facile and time-saving method for preparing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts can accelerate the practical applications of hydrogen energy. In this study, halogen (X = F, Cl, Br and I) doped Ru-RuO₂ on carbon cloth (CC) (X-Ru-RuO₂/MCC) was synthesized via an ultrafast microwave-assisted method for 30 s. Particularly, the doped Br (Br-Ru-RuO₂/MCC) significantly improved the electrocatalytic performances of the catalyst through the regulation of electronic structures. Then, the Br-Ru-RuO₂/MCC catalyst featured HER overpotentials of 44 mV and 77 mV in 1.0 M KOH and 0.5 M H₂SO₄, and the OER overpotential of 300 mV at 10 mA cm^-2 in 1.0 M KOH. This study provides a novel method for developing of halogen-doped catalysts.

Strain Engineering in Ni-Co-Mn-Sn Magnetic Shape Memory Alloys: Influence on the Magnetic Properties and Martensitic Transformation

Ni-Mn-Sn ferromagnetic shape memory alloys, which can be stimulated by an external magnetic field, exhibit a fast response and have aroused wide attention. However, the fixed and restricted working temperature range has become a challenge in practical application. Here, we introduced strain engineering, which is an effective strategy to dynamically tune the broad working temperature region of Ni-Co-Mn-Sn alloys. The influence of biaxial strain on the working temperature range of Ni-Co-Mn-Sn alloy was systematically investigated by the ab initio calculation. These calculation results show a wide working temperature range (200 K) in Ni₁₄Co₂Mn₁₃Sn₃ FSMAs can be achieved with a slight strain from 1.5% to -1.5%, and this wide working temperature range makes Ni₁₄Co₂Mn₁₃Sn₃ meet the application requirements for both low-temperature and high-temperature (151-356 K) simultaneously. Moreover, strain engineering is demonstrated to be an effective method of tuning martensitic transformation. The strain can enhance the stability of the Ni₁₄Co₂Mn₁₃Sn₃ martensitic phase. In addition, the effects of strain on the magnetic properties and the martensitic transformation are explained by the electronic structure in Ni₁₄Co₂Mn₁₃Sn₃ FSMAs.