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Reversible electrodeposition and dissolution of manganese oxide (MnO2) represent an emerging electrochromic system. However, challenges such as “dead MnO2” formation, limited optical modulation across a narrow wavelength range, and difficulties in scaling up have significantly hindered the development of MnO2reversible electrodeposition-based electrochromic windows. In this work, we introduced Fe2+/Fe3+mediator ions into the electrolyte to suppress the Jahn–Teller effect, thereby preventing the formation of “dead MnO2” and achieving stable and reversible MnO2deposition/dissolution. Furthermore, by employing WO3as the counter electrode, we developed a complementary electrochromic device based on ion insertion and metal oxide deposition. This complementary system exhibits color neutrality in the colored state and high optical contrast across the entire visible spectrum, with an average optical modulation of 67.3%, excellent cycling stability (85.0% retention after 3000 cycles), and capability to switch uniformly over areas as large as 100 cm2.

Recently, the development of high-rate performance lithium-ion batteries is crucial for the development of next-generation energy storage systems. Nanoarchitecturing of the electrode material is a common strategy to improve the effective Li+diffusion transport rate. However, this method often results in a reduction of volumetric energy density and battery stability. In this work, we propose a different strategy by synthesizing submicron-sized Ti2Nb10O29(s-TNO) as a durable high-rate anode material using a facile and scalable solution combustion method, eliminating the dependence nanoarchitectures. The s-TNO electrode material exhibits a large tunnel structure and an excellent pseudocapacitive performance. The results show that this electrode material delivers a commendable reversible capacity of 238.7 mAh g–1at 0.5 C and retains 78.2% of its capacity after 10,000 cycles at 10 C. This work provides a valuable guide for the synthesis of submicron-structured electrode materials using the solution combustion method, particularly for high-capacity, high-rate, and high-stability electrode materials.

For steam tubes used in thermal power plant, the inner and outer walls were operated in high-temperature steam and flue gas environments respectively. In this study, structure, microstructure and chemical composition of oxide films on inner and outer walls of ex-service low Cr ferritic steel G102 tube and ex-service high Cr ferritic steel T91 tube were analyzed. The oxide film was composed of outer oxide layer, inner oxide layer and internal oxidation zone. The outer oxide layer on the original surface of tube had a porous structure containing Fe oxides formed by diffusion and oxidation of Fe. More specially, the outer oxide layer formed in flue gas environment would mix with coal combustion products during the growth process. The inner oxide layer below the original surface of tube was made of Fe–Cr spinel. The internal oxidation zone was believed to be the precursor stage of inner oxide layer. The formation of internal oxidation zone was due to O diffusing along grain boundaries to form oxide. There were Fe–Cr–Si oxides discontinuously distributed along grain boundaries in the internal oxidation zone of G102, while there were Fe–Cr oxides continuously distributed along grain boundaries in that of T91.

In the present study, the microstructure, fracture toughness, and fracture behavior of Inconel 617B narrow gap tungsten inert gas (NG-TIG) welded joint were investigated systematically at the designed service temperature of 700 °C. Fracture toughness (J 0.2) of base metal (BM) and heat affected zone (HAZ) was higher than that of weld metal (WM). In HAZ and BM, strain mainly localised at grain boundaries with large misorientation and there were lots of coincidence site lattice (CSL) ∑3 boundaries related to twins inside grains, which led to the much higher fracture toughness of BM and HAZ than WM. The high numbers of twins as well as the less serious strain localization at grain boundaries resulted in the most outstanding fracture toughness of BM. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDs) are a category of promising two-dimensional (2D) materials for the optoelectronic devices, and their unique characteristics include tunable band gap, nondangling bonds as well as compatibility to large-scale fabrication, for instance, chemical vapor deposition (CVD). MoS2is one of the first TMDs that is well studied in the photodetection area widely. However, the low photoresponse restricts its applications in photodetectors unless the device is applied with ultrahigh source–drain voltage (VDS) and gate voltage (VGS). In this work, the photoresponse of a MoS2photodetector was improved by a chemical in situdoping method using gold chloride hydrate. The responsivity and specific detectivity were increased to 99.9 A/W and 9.4 × 1012Jones under low VDS(0.1 V) and VGS(0 V), which are 14.6 times and 4.8 times higher than those of a pristine photodetector, respectively. The photoresponse enhancement results from chlorine n-type doping in CVD MoS2which reduces the trapping of photoinduced electrons and promotes the photogating effect. This novel doping strategy leads to great applications of high-performance MoS2photodetectors potentially and opens a new avenue to enhance photoresponse for other 2D materials.

Two types of vertical 3D nanostructures were successfully fabricated using simple hydrothermal and heat treatment processes for hydrogen evolution reaction and glycerol oxidation reaction (GOR).Hydrogen production at a lower potential was achieved by replacing oxygen evolution reaction with GOR, reducing the device potential by approximately 300 mV. Additionally, organic membranes were used as separators, avoiding the use of expensive anion exchange membranes.

Replacing commercial noble metal catalysts with earth-abundant metal catalysts for hydrogen production is an important research direction for electrolytic water. Improving the catalytic performance of non-noble metals while maintaining stability is a key challenge for alkaline hydrogen evolution. Herein, we combined alkali etching and surface phosphating to regulate the properties of Cr-doped CoMoO4material, forming a surface structure in which amorphous cobalt phosphate and Cr-doped Co(Mo)Oxcoexist. As expected, the as-prepared catalytic material exhibits remarkable hydrogen evolution activity in 1.0 M KOH, only requiring a low overpotential of 52.7 mV to achieve a current density of 10 mA cm–2, and can maintain this current density for 24 h. The characterization and analysis of the catalyst before and after the stability test reveal that the Cr doping and surface engineering (i.e., alkali etching and phosphating) synergistically increase the adsorption and dissociation of water, optimize the desorption of H, and ultimately accelerate hydrogen evolution. This work provides a new strategy for tailoring nonprecious metal materials to improve the hydrogen production from water electrolysis.

Vanadium dopant into NiFe LDH nanosheets can not only favor mild self-reduction of Pt ions into clusters, but also boost the water-splitting kinetics of the resulting Pt/NiFeV LDH nanocomposites via regulating the interfacial electron redistribution. This work can spark inspiration of designing other bifunctional electrocatalysts toward efficient energy conversion and storage.