Search

Surface modification of oxygen evolution reaction (OER) cocatalysts is a promising approach to improve PEC water oxidation activity by accelerating the surface charge injection efficiency and catalytic reaction kinetics. However, the PEC performance is still restricted by inefficient charge transfer at the semiconductor/cocatalyst interface. In this study, ultrathin Ti3C2 nanosheets, serving as a highly efficient hole transport layer, were introduced into the Fe2O3/CoAl-layered double hydroxide (LDH) interface. The obtained Fe2O3–Ti3C2–CoAl photoanodes exhibited a significantly improved photocurrent density of 2.1 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (RHE) under AM 1.5G illumination. In this system, the Ti3C2 nanolayer not only suppresses the interfacial recombination of photogenerated carriers but also facilitates efficient hole transfer from Fe2O3 to the OER cocatalyst, thus promoting the PEC performance. This study provides a new guideline for optimizing the charge transfer at the semiconductor/cocatalyst interface. [ABSTRACT FROM AUTHOR]

Si2N2O ceramic foam is developed by the combination of biological foaming (BF) technique and direct ink writing (DIW). The effect of yeast content on the rheological properties of inks and phase composition, microstructure, and mechanical properties of ceramic foam are systematically investigated. The inks consist of different proportions of yeast suspension and ceramic start powder suspension that exhibit superior printing behavior and proper fermentation capacity. Yeast cells and additives derived from commercial active yeast are fully utilized as BF agent, nutrient, and emulsifier. The variation of yeast contents bring about the evolution of phases, pores density, and mechanical properties of ceramic parts. The Si2N2O foams with porosities from 61.5 ± 4.3% to 71.0 ± 4.5% are successfully fabricated. The corresponding compressive strength decreases from 33.1 ± 2.6 to 8.3 ± 1.5 MPa. As a result, a promising reference for the design and preparation of BF ceramic ink and hierarchical ceramic foam based on DIW is provided. [ABSTRACT FROM AUTHOR]

Water remediation using semiconductor photocatalysts under visible light (VL) irradiance appears as a more sustainable technology option due to the greater penetration depth. Consequently, the overall band spectrum of VL has received significant attention to providing solutions to secure clean water resources over the past few decades. This research developed an innovative approach to enhancing the visible light susceptibility of semiconductor-based photocatalytic composites Ag 10 Si 4 O 13 /TiO 2 (ASO/TO). The intrinsic properties of TO and electron donor ability of ASO lend synergistically to the generation of a narrow bandgap semiconductor. A feasible wet-chemistry method was found to engineer the electronic properties of ASO/TO under VL for rapid decolorization of methylene blue (MB). Inhibition experiments with several agents confirmed that the decolorization proceeds through the generation of hydroxyl radical species assisted by hole carrier generation at the ASO junction. The rate of MB decomposition followed a pseudo-first-order kinetic profile (98.2% within 35 mins under ambient conditions with 5 ppm of 2:1 ASO/TO and 20 ppm of MB). The XRD/XPS spectroscopic analysis confirms the electronic polarization of distorted SiO 4 tetrahedral units coordinated to Ag-O, forming a double dumbbell double-helical structure. The staggered bandgap of these composite photocatalysts is associated with the Ag-Ag d10/sp hybridization and dispersive conduction band. At the same time, the 2p orbitals of TiO 2 showed a less dispersive band due to the availability of d -orbitals. The generated Ag 10 Si 4 O 13 (ASO) based ferroelectric materials allow amplifying its frequency due to internal polarization along the c-axis. The electrochemical evaluation also showed that the interface charge transfer resistance was lowered relative to TiO 2 , facilitating the efficacy of photocatalytic reactivity, where the generation of holes as charge carriers was the rate-limiting step. The novel nano-engineering strategy providing highly active photocatalysis can open new horizons for VL applications. [Display omitted] • Unique d10 and sp/p configurations in its electronic structure, yield high photocatalysis. • Ferroelectric p-block photocatalyst fabrication, by bandgap engineering. • The efficient charge due to electric field in ASO from distorted SiO 4 chain structure. [ABSTRACT FROM AUTHOR]

The performance of carbon-based materials as negative electrodes for supercapacitors can be effectively enhanced through the method like increasing the surface area and active sites as well as heteroatoms doping, while the limited capacitance caused by the surface adsorption mechanism restricts the further improvement of capacitance. Herein, we design hollow and porous FeP spheres (H-FeP) in-situ encapsulated into 3D honeycomb-like porous graphitic N, P-codoping carbon (PGNPC) by a unique post-annealing strategy. The post-annealing process acts as an efficient modification strategy in two aspects: the formation of a porous graphitic carbon framework during the catalytic reaction between iron oxide with carbon and the morphology changing from solid to hollow by introducing the Kirkendall diffusion process. With the synergetic effect of introducing hollow FeP into carbon, the N, P-codoping and 3D porous graphitic carbon framework ensure the as-prepared materials with enhanced performance for negative electrodes. Thus, H-FeP@PGNPC materials display outstanding specific capacitance (696 F g−1), high rate capacity and cycling stability. Using multi-shelled Mn 3 O 4 encapsulated in rGO as the positive electrode, the assembled asymmetric supercapacitor exhibits high specific capacitance and energy density with negligible capacity loss (retain 90% after 5000 cycles). [Display omitted] • Novel in-situ encapsulated hollow FeP into N,P-codoped porous graphenic framework obtained through a high-yield process. • The catalytic reaction caused by the post-annealing process provides extra pseudocapacitive contributions. • The porosity and hollow structure of FeP manipulated by Kirkendall effect. • Porous graphenic framework simultaneously acts as the buffer layer and expressway for electrons transport. [ABSTRACT FROM AUTHOR]