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Thermoelectric generators held great promise through energy harvesting from waste heat. Their practical application, however, is greatly constrained by poor raw material utilization and tedious processing in fabricating desired shapes. Herein, a state‐of‐the‐art process is reported for 3D printing the half‐Heusler (Nb0.88Hf0.12FeSb) thermoelectric material using laser powder bed fusion (LPBF). The multi‐dimensional intra‐ and inter‐granular defects created by this process greatly suppress thermal conductivity by providing numerous phonon scattering centers. The resulting LPBF‐fabricated half‐Heusler exhibits a high figure of merit ≈1.2 at 923 K and a single‐leg maximum efficiency of ≈3.3% at a temperature difference (ΔT) of 371 K. Hafnium oxide nanoparticles generated during LPBF effectively prevent crack propagation, ensuring competent mechanical performance and reliable thermoelectric output. The findings highlight the significant potential of LPBF in driving the next industrial revolution of highly efficient and customizable thermoelectric materials. [ABSTRACT FROM AUTHOR]

Heterostructural engineering and noble metal coupling are effective strategies to optimize semiconductor photocatalytic materials. In this work, (Ag, Mn2O3)-codecorated ZnO nanoparticles with different Mn2O3 contents (0–10 mol%) were synthesized by integrating the two strategies by a facile two-step polymer network-gel process. The photocatalytic activity of Ag/ZnO (AZM0) was significantly enhanced with the optimum Mn2O3 molar ratio of 3 mol%. The degradation efficiency of AZM3 is ∼3 times and ∼4.8 times higher than that of AZM0 for the degradation of methylene blue (MB) upon exposure to simulated sunlight and visible light, respectively. Also, this ternary nanocomposite exhibits enhanced gas sensing performance towards NO2 under ultraviolet/visible light irradiation at room temperature. The analysis of its microstructural, optical and photoelectrical characteristics suggests the synergistic coupling effects of Ag and Mn2O3, in which the significantly enhanced visible light response and hetero-interface charge carrier migration are the critical factors for the improvement of photocatalytic efficiency and gas sensing activity. Furthermore, the effects of recycling ability, the influence of the initial solution pH, the catalyst dosage and the main active species during the catalysis process on photocatalytic activity were explored. This study develops a feasible pathway to consciously construct multiheterostructures for enhancing the photocatalytic activity with great potential applications in toxic pollution abatement and noxious gas detection. [ABSTRACT FROM AUTHOR]

The construction of heterostructured photocatalyst with an appropriate energy band structure will help realize highly efficient photo-excited charge separation. In this study, ternary CuO/CeO2/ZnO nano-particle (NP) composites were synthesized by a facile two-step sol-gel method, which exhibit significantly enhanced photocatalytic degradation performance for various organic pollutants under UV and visible light excitation. The photo-responses to both UV and visible light, as well as the visible light absorption and utilization rates of ZnO are found to be synergistically intensified by CeO2 and CuO co-coupling. The first-order kinetic constants (K) of 3%CuO/CeO2/ZnO for methylene blue (MB) degradation are ~3.9, ~4.1 and ~4.8 times higher than ZnO under UV light, visible light and simulated sunlight illumination, respectively. The roles of CuO and CeO2 in optical properties and photo-degradation under UV and visible light were explored. Besides, the photogenic holes (h+) of ZnO, CeO2, and the produced hydroxyl radicals (·OH) are proved to be the main active species under UV light. Dissimilarly, under visible light, the superoxide radicals (·O2−) formed by the reactions between oxygen molecules and the photo-generated electrons (e−) of CuO moving towards the catalysts surface are also found to be important for promoting dye decomposition. The improved photo-responses, the well-matched band structure that facilitates charge transfer processes, and the highly efficient utilization of the photo-excited carriers of the ternary nano-heterostructure are suggested to be the key factors for the remarkable enhancement of photocatalytic performance of ZnO nano-photocatalyst. This work offers a low-cost strategy to acquire highly active UV and visible light-driven photocatalyst. [ABSTRACT FROM AUTHOR]

Thermoelectric generators held great promise through energy harvesting from waste heat. Their practical application, however, is greatly constrained by poor raw material utilization and tedious processing in fabricating desired shapes. Herein, a state-of-the-art process is reported for 3D printing the half-Heusler (Nb 0.88 Hf 0.12 FeSb) thermoelectric material using laser powder bed fusion (LPBF). The multi-dimensional intra- and inter-granular defects created by this process greatly suppress thermal conductivity by providing numerous phonon scattering centers. The resulting LPBF-fabricated half-Heusler exhibits a high figure of merit ≈1.2 at 923 K and a single-leg maximum efficiency of ≈3.3% at a temperature difference (ΔT) of 371 K. Hafnium oxide nanoparticles generated during LPBF effectively prevent crack propagation, ensuring competent mechanical performance and reliable thermoelectric output. The findings highlight the significant potential of LPBF in driving the next industrial revolution of highly efficient and customizable thermoelectric materials., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Heterostructural engineering and noble metal coupling are effective strategies to optimize semiconductor photocatalytic materials. In this work, (Ag, Mn2O3)-codecorated ZnO nanoparticles with different Mn2O3 contents (0-10 mol%) were synthesized by integrating the two strategies by a facile two-step polymer network-gel process. The photocatalytic activity of Ag/ZnO (AZM0) was significantly enhanced with the optimum Mn2O3 molar ratio of 3 mol%. The degradation efficiency of AZM3 is ∼3 times and ∼4.8 times higher than that of AZM0 for the degradation of methylene blue (MB) upon exposure to simulated sunlight and visible light, respectively. Also, this ternary nanocomposite exhibits enhanced gas sensing performance towards NO2 under ultraviolet/visible light irradiation at room temperature. The analysis of its microstructural, optical and photoelectrical characteristics suggests the synergistic coupling effects of Ag and Mn2O3, in which the significantly enhanced visible light response and hetero-interface charge carrier migration are the critical factors for the improvement of photocatalytic efficiency and gas sensing activity. Furthermore, the effects of recycling ability, the influence of the initial solution pH, the catalyst dosage and the main active species during the catalysis process on photocatalytic activity were explored. This study develops a feasible pathway to consciously construct multiheterostructures for enhancing the photocatalytic activity with great potential applications in toxic pollution abatement and noxious gas detection.