A general one-pot solvothermal process was explored to prepare BiOX (X = Cl, Br, I) powders by employing ethylene glycol as the solvent. The as-prepared BiOX powders were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV−vis diffuse reflectance spectroscopy, and nitrogen sorption. The resulting BiOX samples were phase-pure and of hierarchical microspheres consisting of nanoplates. The band gaps of the as-prepared powders were estimated to about 3.22, 2.64, and 1.77 eV for BiOCl, BiOBr, and BiOI, respectively. On the basis of characterization results, we proposed a possible process for the growth of hierarchical BiOX nanoplate microspheres. Moreover, we evaluated their photocatalytic activities on the degradation of methyl orange and compared them with TiO2 (Degussa, P25) under UV−vis light irradiation and C-doped TiO2 under visible light (λ > 420 nm) irradiation, respectively. It was found that al...

Generalized One-Pot Synthesis, Characterization, and Photocatalytic Activity of Hierarchical BiOX (X = Cl, Br, I) Nanoplate Microspheres

Heterogeneous photocatalysis that employs photo-excited semiconductor materials to reduce water and oxidize toxic pollutants upon solar light irradiation holds great prospects for renewable energy substitutes and environmental protection. To utilize solar light effectively, the quest for highly active photocatalysts working under visible light has always been the research focus. Layered BiOX (X = Cl, Br, I) are a kind of newly exploited efficient photocatalysts, and their light response can be tuned from UV to visible light range. The properties of semiconductors are dependent on their morphologies and compositions as well as structures, and this also offers the guidelines for design of highly-efficient photocatalysts. In this review, recent advances and emerging strategies in tailoring BiOX (X = Cl, Br, I) nanostructures to boost their photocatalytic properties are surveyed.

Engineering BiOX (X = Cl, Br, I) nanostructures for highly efficient photocatalytic applications

https://dr.ntu.edu.sg/bitstream/10356/88603/1/Anisotropy%20and%20heterogeneity%20of%20microstructure%20and%20mechanical%20properties%20in%20metal%20additive%20manufacturing-%20A%20critical%20review.pdf

Anisotropy and heterogeneity of microstructure and mechanical properties in metal additive manufacturing: A critical review

High entropy alloys: A focused review of mechanical properties and deformation mechanisms

Crystallographic features of lath martensite in low-carbon steel

Effect of long-period stacking ordered phase on mechanical properties of Mg97Zn1Y2 extruded alloy

Catalytic performance of BiOCl catalyst has been investigated for the oxidative cracking of n -butane to lower alkenes. Results are compared with those of isostructural LaOCl and SmOCl catalysts. On the BiOCl catalyst, oxidative dehydrogenation and combustion were major reactions at ∼500°C; above ∼600°C oxidative cracking reaction to produce ethylene and propylene began to be significant. At the temperature as low as 625°C, 52% yield of overall C 2 –C 4 alkenes was achieved, and then decreased above this temperature. The conversions of n -butane and oxygen were maintained constants within 6 h periods at the reaction temperatures of 550 and 600°C. However, both conversions decreased slightly with time-on-stream at 650°C. BiOCl catalyst shows rather high alkenes’ selectivity and suppresses deep oxidation reactions for the oxidative cracking of n -butane, as compared to the LaOCl and SmOCl catalysts. The overall yield of C 2 –C 4 alkenes for the BiOCl catalyst is higher than the values for the LaOCl and SmOCl catalysts over the temperature range of 500–600°C.

Oxidative catalytic cracking of n-butane to lower alkenes over layered BiOCl catalyst

Preparation and Characterization of Open Tunnel Oxide α-MnO2 Precipitated by Ozone Oxidation

This paper clarified a novel strategy to improve the tensile properties of the Ti-48Al-2Cr-2Nb alloys fabricated by electron beam melting (EBM), via the finding of the development of unique layered microstructure composed of duplex-like fine grains layers and coarser γ grains layers. It was clarified that the mechanical properties of the alloy fabricated by EBM can be controlled by varying an angle θ between EBM-building directions and stress loading direction. At room temperature, the yield strength exhibits high values more than 550 MPa at all the loading orientations investigated ( θ  = 0, 45 and 90°). In addition, the elongation at θ  = 45° was surprisingly larger than 2%, owing to the development of this unique layered microstructure. The anisotropy of the yield strength decreased with increasing temperature. All the examined alloys exhibited a brittle-ductile transition temperature of approximately 750 °C and the yield strength and tensile elongation at 800 °C were over 350 MPa and 40%, respectively. By the detailed observation of the microstructure, the formation mechanism of the unique layered microstructure was found to be closely related to the repeated local heat treatment effect during the EBM process, and thus its control is further possible by the tuning-up of the process parameters. The results demonstrate that the EBM process enables not only the fabrication of TiAl products with complex shape but also the control of the tensile properties associated with the peculiar microstructure formed during the process.

Hiroyuki Y. Yasuda

Papers

Effect of long-period stacking ordered phase on mechanical properties of Mg97Zn1Y2 extruded alloy

Oxidative catalytic cracking of n-butane to lower alkenes over layered BiOCl catalyst

Preparation and Characterization of Open Tunnel Oxide α-MnO2 Precipitated by Ozone Oxidation

Effect of building direction on the microstructure and tensile properties of Ti-48Al-2Cr-2Nb alloy additively manufactured by electron beam melting

Plastic deformation behavior of Mg89Zn4Y7 extruded alloy composed of long-period stacking ordered phase