Optimizing the Atom Substitution of Er in WS₂ Nanosheets for High-Performance Photoelectrochemical Applications

Introducing the density of states or defects within the band gap in two-dimensional nanomaterials by rare-earth (RE) element substitution would make them potential candidates for application in next-generation optoelectronic devices. Furthermore, doping with RE elements possessing fine-structured spectral emission and absorption can improve the fundamental research and technological applications of two-dimensional nanomaterial-based photoelectrochemical (PEC) activity due to abundant active sites and low interfacial contact resistance with the electrolyte. Herein, an Er-doping strategy is utilized for the synthesis of Er-doped WS2 nanosheets to simultaneously achieve both upconversion and downconversion emissions, which can efficiently absorb more solar light for PEC activity. We first report a two-step method combining magnetic sputtering and sulfurization to synthesize Er-doped WS2 nanosheet-based electrodes. The effect of Er doping into a single-phase hexagonal-structured WS2 (p-type semiconductor)-based electrode on PEC activity is investigated and compared with pristine WS2 counterparts under one standard sun condition. Results indicate that a photocurrent density of −20 μA·cm–2 at −0.21 V versus RHE (reversible hydrogen electrode) with an enhancement factor of ∼200-fold due to a wider absorbance range (400–808 nm) and a decreased overpotential for hydrogen reduction are achieved. Moreover, the resistance of the Er-doped WS2 electrode is found to be decreased from 500 to 28 kΩ, with nearly a 20-fold decrease compared with that of the pristine WS2 counterparts, contributing to the higher efficiency in electron transfer into the electrolyte. The mechanism is confirmed by Monte Carlo simulations and first-principles calculations. The Er-doped WS2 nanosheets are therefore a promising substitute for noble metals in PEC applications

Flexible, Wearable, and Ultralow-Power-Consumption Electronic Skins Based on a Thermally Reduced Graphene Oxide/Carbon Nanotube Composite Film

Based on a thermally reduced graphene oxide (rGO)/carbon nanotube (CNT) composite film, two kinds of flexible, wearable, and ultralow-power-consumption electronic skins (E-skins) are prepared. They have been used to successfully perceive the signals of stretch, flexion, temperature, and pressure, and their gauge factors (GFs) are 233, 2.37 rad–1, 5.53 × 10–4 °C–1, and 1.58 kPa–1, as the mass fraction of graphene is 20% in the composite film. Compared with the E-skins based on pure rGO film, our E-skins have larger stretching stain (ε) and bending angle (θ) ranges and higher temperature- and pressure-based GF values. Furthermore, the prepared E-skins have been successfully applied in various fields, and their ultralow power consumption has also been confirmed to be below 72 nW in wearable device applications

Flexible, Wearable, and Ultralow-Power-Consumption Electronic Skins Based on a Thermally Reduced Graphene Oxide/Carbon Nanotube Composite Film

Based on a thermally reduced graphene oxide (rGO)/carbon nanotube (CNT) composite film, two kinds of flexible, wearable, and ultralow-power-consumption electronic skins (E-skins) are prepared. They have been used to successfully perceive the signals of stretch, flexion, temperature, and pressure, and their gauge factors (GFs) are 233, 2.37 rad–1, 5.53 × 10–4 °C–1, and 1.58 kPa–1, as the mass fraction of graphene is 20% in the composite film. Compared with the E-skins based on pure rGO film, our E-skins have larger stretching stain (ε) and bending angle (θ) ranges and higher temperature- and pressure-based GF values. Furthermore, the prepared E-skins have been successfully applied in various fields, and their ultralow power consumption has also been confirmed to be below 72 nW in wearable device applications

Flexible, Wearable, and Ultralow-Power-Consumption Electronic Skins Based on a Thermally Reduced Graphene Oxide/Carbon Nanotube Composite Film

Based on a thermally reduced graphene oxide (rGO)/carbon nanotube (CNT) composite film, two kinds of flexible, wearable, and ultralow-power-consumption electronic skins (E-skins) are prepared. They have been used to successfully perceive the signals of stretch, flexion, temperature, and pressure, and their gauge factors (GFs) are 233, 2.37 rad–1, 5.53 × 10–4 °C–1, and 1.58 kPa–1, as the mass fraction of graphene is 20% in the composite film. Compared with the E-skins based on pure rGO film, our E-skins have larger stretching stain (ε) and bending angle (θ) ranges and higher temperature- and pressure-based GF values. Furthermore, the prepared E-skins have been successfully applied in various fields, and their ultralow power consumption has also been confirmed to be below 72 nW in wearable device applications

High-Entropy Strategy for Improved Mechanical and Energy Storage Properties in BaTiO₃–BiFeO₃‑Based Ceramics

Dielectric capacitors are employed extensively due to their exceptional performance, including a rapid charge–discharge speed and superior power density. However, their practical implementation is hindered by constraints in energy-storage density (ESD), efficiency (ESE), and thermal stability. To achieve domain engineering and improved relaxor behavior in 0.67BiFeO3-0.33BaTiO3-based Pb-free ceramics, the concerns have been addressed here by employing a synergistic high-entropy strategy involving the design of the composition of Sr(Mg1/6Zn1/6Ta1/3Nb1/3)O3 with B-site multielement coexistence and high configuration entropy. Remarkably, in (0.67-x)BiFeO3-0.33BaTiO3-xSr(Mg1/6Zn1/6Ta1/3Nb1/3)O3 ceramics with x = 0.08, a good ESE (η) of 75% and a recoverable ESD (Wrec) of 2.4 J/cm3 at 190 kV/cm were attained together with an ultrahigh hardness of ∼7.2 GPa. The high-entropy strategy, which is tailored by an increase in configuration entropy, can be attributed to the superior mechanical and ES properties. It also explains the enhanced random field and relaxation behavior, the structural coexistence of ferroelectric rhombohedral (R3c) and nonpolar pseudocubic (Pm-3m) symmetries, the decreased domain size, and evenly distributed polar nanoregions (PNRs). Moreover, improved thermal stability and outstanding frequency stability are also obtained. By boosting the configuration entropy, BiFeO3–BaTiO3 materials dramatically improved their complete energy storage performance. This suggests that designing high-performance dielectrics with high entropy can be a convenient yet effective technique, leading to the development of advanced capacitors