Hebei University of Science and Technology

About: Hebei University of Science and Technology is a education organization based out in Shijiazhuang, China. It is known for research contribution in the topics: Catalysis & Fuzzy logic. The organization has 7342 authors who have published 5832 publications receiving 50239 citations.

Ti3C2 MXene co-catalyst on metal sulfide photo-absorbers for enhanced visible-light photocatalytic hydrogen production.

Abstract: Scalable and sustainable solar hydrogen production through photocatalytic water splitting requires highly active and stable earth-abundant co-catalysts to replace expensive and rare platinum. Here we employ density functional theory calculations to direct atomic-level exploration, design and fabrication of a MXene material, Ti3C2 nanoparticles, as a highly efficient co-catalyst. Ti3C2 nanoparticles are rationally integrated with cadmium sulfide via a hydrothermal strategy to induce a super high visible-light photocatalytic hydrogen production activity of 14,342 μmol h−1 g−1 and an apparent quantum efficiency of 40.1% at 420 nm. This high performance arises from the favourable Fermi level position, electrical conductivity and hydrogen evolution capacity of Ti3C2 nanoparticles. Furthermore, Ti3C2 nanoparticles also serve as an efficient co-catalyst on ZnS or ZnxCd1−xS. This work demonstrates the potential of earth-abundant MXene family materials to construct numerous high performance and low-cost photocatalysts/photoelectrodes.

Low-molecular-mass gels responding to ultrasound and mechanical stress: towards self-healing materials

Abstract: In this review, we focus on the types of smart supramolecular gels whose self-assembly processes are affected or even triggered by physical forces including sonication and mechanical stress (mechanical force). The types of gels that are responsive to sonication and mechanical stress are examined and summarised. The gels exhibit non-covalent interactions among the gelator molecules and show dynamic and reversible properties controlled by the stimuli. Upon stimulation, the gelators cause instant and in situ gelation of organic solvents or water with different modes and outcomes of self-assembly. On the other hand, sonication and mechanical stress, as external factors, can give rise to dynamic changes in microscopic morphology, optical properties, etc. Certain thixotropic supramolecular gels exhibit perfect self-healing characteristics. The driving forces and the mechanism of the self-assembly process and the responsive outcome of morphological and spectroscopic changes are discussed. Those supramolecular gels responding to sonication and mechanical stress offer a wide range of applications in fields such as smart and adaptive materials, switches, drug control and release, and tissue engineering.

Preparation of polyaniline-modified TiO2 nanoparticles and their photocatalytic activity under visible light illumination

Abstract: Titanium dioxide nanoparticles were modified by polyaniline (PANI) using ‘in situ’ chemical oxidative polymerization method in hydrochloric acid solutions. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy spectrum (XPS) and UV–vis spectra were carried out to characterize the composites with different PANI contents. The photocatalytic degradation of phenol was chosen as a model reaction to evaluate the photocatalytic activities of the modified catalysts. Results show that TiO2 nanoparticles are deposited by PANI to mitigate TiO2 particles agglomeration. The modification does not alter the crystalline structure of the TiO2 nanoparticles according to the X-ray diffraction patterns. UV–vis spectra reveal that PANI-modified TiO2 composites show stronger absorption than neat TiO2 under the whole range of visible light. The resulting PANI-modified TiO2 composites exhibit significantly higher photocatalytic activity than that of neat TiO2 on degradation of phenol aqueous solution under visible light irradiation (λ ≥ 400 nm). An optimum of the synergetic effect is found for an initial molar ratio of aniline to TiO2 equal to 1/100.

In Situ Microwave-Assisted Synthesis of Porous N-TiO2/g-C3N4 Heterojunctions with Enhanced Visible-Light Photocatalytic Properties

Abstract: An in situ microwave-assisted synthesis approach has been developed to prepare N-TiO2/g-C3N4 composites using H2TiO3 as the reactant and NH3·H2O as the N-doping source. In this way, the N-TiO2/g-C3N4 composite catalysts have a porous structure and large surface areas, which increase the contact area of pollutants. Degradation of rhodamine B (Rh B) and methylene blue (MB) were carried out to evaluate the photocatalytic activity of samples under visible light irradiation. N-TiO2/g-C3N4 composite with 40 wt % N-TiO2 exhibits the highest photocatalytic activity and the optimal temperature is 400 °C. The increased photocatalytic activity of N-TiO2/g-C3N4 composites can be attributed to the formation of the heterojunction between N-TiO2 and g-C3N4, which suppresses the recombination of photoinduced electron–hole pairs. The tests of radical scavengers confirmed that •O2– was the main reactive species during the photocatalytic process.