Beaded-stream-like nanoneedles array based on earth-abundant and inexpensive CoSe2 efficiently splits water into hydrogen.

One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni-nanocluster loaded black TiO (Ni/TiO ) with built-in dual active sites for selective photocatalytic CO conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO (P-25). An insight into the mechanisms of interfacial charge transfer and product formation is explored.

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Tuning the electronic band structure of black titania to improve photocatalytic performance through conventional band engineering methods has been challenging because of the defect-induced charge carrier and trapping sites. In this study, KSCN-modified hydrogenated nickel nanocluster-modified black TiO 2 (SCN−H−Ni−TiO 2 ) exhibits enhanced photocatalytic CO 2 reduction due to the interfacial dipole effect. Upon combining the experimental and theoretical simulation approach, the presence of an electrostatic interfacial dipole associated with chemisorption of SCN has dramatic effects on the photocatalyst band structure in SCN− H−Ni−TiO 2 . An interfacial dipole possesses a more negative zeta potential shift of the isoelectric point from 5.20 to 3.20, which will accelerate the charge carrier separation and electron transfer process. Thiocyanate ion passivation on black TiO 2 demonstrated an increased work function around 0.60 eV, which was induced by the interracial dipole effect. Overall, the SCN− H−Ni−TiO 2 photocatalyst showed an enhanced CO 2 reduction to solar fuel yield by 2.80 times higher than H−Ni−TiO 2 and retained around 88% product formation yield after 40 h.

Developing novel materials is crucial to overcoming the performance degradation of lithium-ion batteries (LIBs) for low-temperature applications. In this work, we demonstrate a novel copper zinc tin sulfide (Cu 2 ZnSnS 4 , CZTS) thin film with nanowalls structure as the anode material in thin-film LIBs for low-temperature applications. The quaternary CZTS synthesized by a simple hydrothermal method shows a higher reversible capacity of 475 mAh g −1 after 200 cycles at −10 °C with the EC/ DEC/DMC-based electrolyte in comparison with the graphite electrode (110 mAh g −1 after 100 cycles at −10 °C). The effects of temperature and electrolyte systems including EC/DEC-and EC/ DEC/DMC-based electrolytes on the cycling performance are studied. The faster Li-ion transport in the electrolyte−electrode interface of the CZTS anode material is obtained in the EC/DEC/DMC-based electrolyte at −10 °C. In addition, the depthprofiling XPS results of the CZTS anode reveal that a solid electrolyte interphase (SEI) layer with less carbon content is formed in the EC/DEC/DMC-based electrolyte likely associated with the interfacial stability at low temperature. The enhanced cycling performance of CZTS could be attributed to its improved interfacial stability and Li + diffusion, along with the formation of an interconnected active material architecture at low temperature.

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Defect engineering is of great interest to the two-dimensional (2D) materials community. If nonmagnetic transition-metal dichalcogenides can possess room-temperature ferromagnetism (RTFM) induced by defects, then they will be ideal for application as spintronic materials and also for studying the relation between electronic and magnetic properties of quantum-confined structures. Thus, in this work, we aimed to study gamma-ray irradiation effects on MoS2, which is diamagnetic in nature. We found that gamma-ray exposure up to 9 kGy on few-layered (3.5 nm) MoS2 films induces an ultrahigh saturation magnetization of around 610 emu/cm3 at RT, whereas no significant changes were observed in the structure and magnetism of bulk MoS2 (40 nm) films even after gamma-ray irradiation. The RTFM in a few-layered gamma-ray irradiated sample is most likely due to the bound magnetic polaron created by the spin interaction of Mo 4d ions with trapped electrons present at sulfur vacancies. In addition, density functional theory (DFT) calculations suggest that the defect containing one Mo and two S vacancies is the dominant defect inducing the RTFM in MoS2. These DFT results are consistent with Raman, X-ray photoelectron spectroscopy, and ESR spectroscopy results, and they confirm the breakage of Mo and S bonds and the existence of vacancies after gamma-ray irradiation. Overall, this study suggests that the occurrence of magnetism in gamma-ray irradiated MoS2 few-layered films could be attributed to the synergistic effects of magnetic moments arising from the existence of both Mo and S vacancies as well as lattice distortion of the MoS2 structure.