Composites of Co-Doped Graphitic C₃N₄ Nanosheets and TiO₂ Nanoparticles for Electrorheological Fluid Applications

Abstract

Herein, composites of Co-doped graphitic C3N4 nanosheets and TiO2 nanoparticles (Co-C3N4 NSs/TiO2 NPs) were prepared through a two-step synthetic strategy, and their electrorheological (ER) performance under varied electric field strengths was also researched. The microstructure, chemical elements, and surface morphology of materials were studied thoroughly by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) test, and X-ray photoelectron spectroscopy (XPS) measurements. The presence of TiO2 NPs and g-C3N4 was confirmed by XRD and FTIR results. Typical SEM and TEM images revealed the apparent sheet-like nanostructure of Co-C3N4, and the filling of TiO2 NP in-layers was discovered. Meanwhile, BET results indicated the abundant pore structure of Co-C3N4 NSs/TiO2 NP composites. The ER performances of Co-C3N4 NSs/TiO2 NP composites, including shear stress, shear viscosity, and ER efficiency, were examined under different electric field strengths with a high-quality electrorheometer. Interestingly, the obtained Co-C3N4 NSs/TiO2 NP composites exhibited an excellent ER property including an unexpected ER efficiency (up to 196), superior platform area, obvious dielectric loss peak, and high shear stress (more than 600 Pa at 3.0 kV/mm), showing wide application prospects as electrorheological materials.

Structure–Activity Relationship for the Catalytic Hydrogenation of Nitrobenzene by Single Platinum Atoms Supported on Nitrogen-Doped Carbon

“…Figure S7 presents the bonding energy of C 1s and O 1s in Pt/ g -C 3 N 4 , Pt/ pyrrol -N x C, Pt/ ani -N x C, Pt/ pyridine -N x C, and Pt/ ben -C. The spectrum of C 1s could be deconvoluted into six species at 284.8, 285.8, 286.9, 287.7, 288.1, and 288.9 eV, which were corresponding to C–C/C–N/CC, CN, C–O, CO, N–CN, and O–CC, respectively. − the peak at 532.3 eV in O 1s could be assigned to C–O/CO species, and other peaks at 531.3 and 533.6 eV were attributed to −OH and O 2 , respectively, which might be derived from the adsorbed oxygen on the catalyst surface …”

Engineering Conductivity and Performance in Electrorheological Fluids Using a Nanosilica Grafting Approach

“…Flow curves of Glu-600- and Glu@SiO 2 -based fluids demonstrated that typical shear stress plateau at low shear rates. For that reason, the ER activity of the fluids was evaluated using the six-parameter Cho–Choi–Jhon (CCJ) model, which properly describes ER behavior at a wide shear rate region and can be read as follows τ = τ 0 1 + false( t 2 γ̇ false) α + η ∞ ( 1 1 + ( t 3 γ̇ ) β ) γ̇ where τ denotes the shear stress, τ 0 represents the dynamic yield stress, γ̇ is the shear rate, t 2 and t 3 are time constants, α is the parameter related to the initial decrease in stress, and η ∞ is the viscosity at high γ̇, while β can be considered as the corrective term, attaining 0 < β ≤ 1. Figure A–C shows that the experimental data were fitted with the CCJ model (eq ) for the fabricated (5 wt %) ER fluids with high accuracy ( R 2 > 0.94).…”

Construction and excellent photoelectric synergistic anticorrosion performance of Z-scheme carbon nitride/tungsten oxide heterojunctions

“…The diffraction peak at 13.1°c orresponded to the (100) plane due to the planar structure of the triazine unit. 27,28 For the WO 3 material, all characteristic diffraction peaks could be retrieved as the WO 3 (JCPDS no. 83-0950) monoclinic crystal structure.…”