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As a promising electrocatalyst, MoS2 has attracted significant attention for application in the hydrogen evolution reaction (HER). However, the shortcomings such as limited active sites and the inherently low electroconductivity of the 2H-phase MoS2 restrain its application. Tuning of the phase composition (from 2H to 1T phase) and the microstructure of MoS2 have been proposed as effective strategies to improve the catalytic activity of MoS2. However, complicated chemical exfoliation and morphology regulation are generally involved in these process. Herein, we developed a facile hydrothermal method to in situ synthesize hierarchical MoS2 nanorods with mixed 1T and 2H phases. The coexisting 1T phase can provide more active sites and improve the electronic conductivity of the nanorods. In addition, the Schottky barriers formed at the boundaries of the 1T and 2H phases can improve the conductivity. Moreover, the hierarchical structure can improve the contact area between the MoS2 catalyst and the electrolyte, and the rod-like one-dimensional structure of the catalyst favors fast charge transfer and ion diffusion. Due to these unique properties, the as-synthesized MoS2 nanocatalyst exhibits excellent HER performance with a small overpotential of 156 mV at 10 mA cm−2, a small Tafel slope of 47.9 mV per decade, and robust stability. This study provides a guideline for the design of an electrocatalyst with high HER performance in multiscale principles.

Sensitizers play important roles in the practical application of luminescence materials. Sensitizer ions with forbidden transitions usually exhibit smaller absorption regions and low energy transfer efficiencies, while sensitizer ions with allowed transitions tend to generate self-emissions that are too strong to achieve simple sensitization effects. To solve this problem, we propose an approach of modified matrix sensitization. When designing our novel Sc(V, P)O4: Dy3+ nano/submicron particles, we introduced a PO43− group in the host to efficiently separate the VO43− groups. Based on the premise of the large absorption region of the sensitive center, the energy loss by nonradiative transitions due to interactions of VO43− is decreased. Consequently, the strong excitation energy can be transferred to Dy3+ and improve the luminescence efficiency and thermal quenching performance of Dy3+. At the same time, the morphology and size of Sc(V, P)O4: Dy3+ can be tuned in a controlled manner by altering the P5+ content. All the properties have been studied by XRD, SEM, TEM, PL and CL in detail; the results demonstrate that these materials have potential applications in fluorescent lamps and displays.

The CaCO3/biopolymer composite materials have been prepared by a two-step synthesis. The biopolymer was synthesized from chitosan and acrylic acid in supercritical carbon dioxide, then a large scale of novel flowerlike structured calcite CaCO3 on the biopolymer has been synthesized for the first time by the following process of mineralization. The well-defined flowerlike morphology consisting of orderly and regular petals could be tailored by controlling the reaction time. The morphology evolution of CaCO3 was investigated by the XRD, FTIR and SEM. Moreover, the prepared CaCO3/biopolymer composite materials were further characterized by 1H NMR, HRTEM, SAED and XPS, respectively. The experimental results show that the petal possessed a single crystal structure and consisted of stackings of (18). Interestingly, the product is sensitive to the lower laser power by Raman spectra. Based on experimental results, the growth process of formation of a special shape for CaCO3 was also speculated, which indicates that acrylic acid and chitosan played an important role in forming substrates and in following further mineralization of CaCO3.