Molybdenum disulfide has been one of the most studied hydrogen evolution catalyst materials in recent years, but its disadvantages, such as poor conductivity, hinder its further development. Here, we employ the common hydrothermal method, followed by an additional solvothermal method to construct an uncommon molybdenum disulfide with two crystal forms of 1T and 2H to improve catalytic properties. The low overpotential (180 mV) and small Tafel slope (88 mV/dec) all indicated that molybdenum disulfide had favorable catalytic performance for hydrogen evolution. Further conjunctions revealed that the improvement of performance was probably related to the structural changes brought about by the 1T phase and the resulting sulfur vacancies, which could be used as a reference for the further application of MoS₂.

Herein, we report an eco-friendly and simple fluorescent nitrogen-doped carbon quantum dot (N-CQD) biosensor which was synthesized via a hydrothermal method using erhanediamine (EDA) and citric acid (CA) as precursors. The surface functionalization of N-CQDs exhibited a bright blue emission under the excitation wavelength of 350 nm. The obtained N-CQDs were characterized by atomic force microscopy (AFM), Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and transmission electron microscopy. It was found that the surface of the CQDs was successfully functionalized. After that, as-prepared N-CQDs were further applied in Fe(III) detection. Spectroscopic data indicated that fluorescent carbon-based nanomaterials displayed a sensitive response to Fe ³⁺ in the range of 0.5–1000 μ M as a fluorescence sensor in real environmental samples. Furthermore, the results also showed that a novel N-CQD nanomaterial could be employed as an ideal fluorescent Fe(III) probe.

Palladium nanoparticle-bacterial cellulose (PdBC) hybrid nanofibers were synthesized by in-situ chemical reduction method. The obtained PdBC nanofibers were characterized by a series of analytical techniques. The results revealed that Pd nanoparticles were evenly dispersed on the surfaces of BC nanofibers. Then, the as-prepared PdBC nanofibers were mixed with laccase (Lac) and Nafion to obtain mixture suspension, which was further modified on electrode surface to construct novel biosensing platform. Finally, the prepared electrochemical biosensor was employed to detect dopamine. The analysis result was satisfactory, the sensor showed excellent electrocatalysis towards dopamine with high sensitivity (38.4 µA·mM⁻¹), low detection limit (1.26 µM), and wide linear range (5–167 µM). Moreover, the biosensor also showed good repeatability, reproducibility, selectivity and stability and was successfully used in the detection of dopamine in human urine, thus providing a promising method for dopamine analysis in clinical application.