Henan Normal University

About: Henan Normal University is a education organization based out in Xinxiang, China. It is known for research contribution in the topics: Catalysis & Ionic liquid. The organization has 10863 authors who have published 11077 publications receiving 166773 citations.

One-Pot Synthesis of Ag/ZnO Self-Assembled 3D Hollow Microspheres with Enhanced Photocatalytic Performance

Abstract: In this paper, three-dimensional (3D) Ag/ZnO hollow microspheres with different Ag contents were prepared through a facile one-pot hydrothermal method assisted by sodium alginate The samples were structurally characterized by X-ray diffraction, field emission scanning electron microscope, high resolution transmission electron microscope, and X-ray photoelectron spectroscopy It was shown that all samples were composed of metallic Ag and wurtzite ZnO; the 3D Ag/ZnO hollow microspheres were constructed from self-assembled 1D Ag/ZnO nanorods; the surface O species can be categorized to surface hydroxyl oxygen (OH) and crystal lattice oxygen (OL), and the ratio between them varies with different Ag loadings The photocatalytic performance for the degradation of Orange G was also evaluated The results show that such hierarchical Ag/ZnO hollow microspheres exhibit significantly enhanced photocatalytic efficiency Investigation of the relationship of photoluminescence (PL) spectra and surface structure of the

Controllable Perovskite Crystallization by Water Additive for High-Performance Solar Cells

Abstract: A key issue for perovskite solar cells is the stability of perovskite materials due to moisture effects under ambient conditions, although their efficiency is improved constantly. Herein, an improved CH3NH3PbI3−xClx perovskite quality is demonstrated with good crystallization and stability by using water as an additive during crystal perovskite growth. Incorporating suitable water additives in N,N-dimethylformamide (DMF) leads to controllable growth of perovskites due to the lower boiling point and the higher vapor pressure of water compared with DMF. In addition, CH3NH3PbI3−xClx · nH2O hydrated perovskites, which can be resistant to the corrosion by water molecules to some extent, are assumed to be generated during the annealing process. Accordingly, water additive based perovskite solar cells present a high power conversion efficiency of 16.06% and improved cell stability under ambient conditions compared with the references. The findings in this work provide a route to control the growth of crystal perovskites and a clue to improve the stability of organic–inorganic halide perovskites.

A green and scalable route to yield porous carbon sheets from biomass for supercapacitors with high capacity

Abstract: A green and scalable route is developed to prepare hierarchical porous carbon sheets (HPCS) from biomass (cornstalk) directly under an air atmosphere instead of inert gas protection. In addition, the method adopts non-toxic NaCl and KCl mixed salt as reaction media to regulate the activation process, which avoids the corrosive and poisonous KOH and ZnCl2 reagents. Meanwhile, the porous structures of HPCS can be well-manipulated by the salt templates and the etching effects of the oxygen atom as well as the high energy molten salt media. The as-obtained HPCS consist of an ultra-thin sheet structure (∼4.6 nm in thickness) and abundant hierarchical pores, which facilitates electrolyte diffusion and ion transfer. In addition, the high specific surface area of 1588 m2 g−1 provides sufficient active sites and the rich O doping introduces pseudocapacitance. Therefore, the as-prepared HPCS exhibit a high specific capacitance of 407 F g−1 at 1 A g−1 in a three-electrode system. Moreover, the assembled symmetric supercapacitor in a two-electrode system also exhibits an outstanding specific capacitance of 413 F g−1 at 0.5 A g−1, an excellent rate capacity and a long-term cycling stability with 92.6% of initial capacitance retention after 20 000 cycles at 5 A g−1, which are comparable to those of the porous carbons activated with traditional methods. It is expected that this green and facile technique could serve as an effective and scalable method to prepare optimized HPCS with tunable porous structures from biomass for electrochemical energy storage applications.