Carbon nano-materials have been widely used in many fields due to their electron transport, mechanics, and gas adsorption properties. This paper introduces the structure and properties of carbon nano-materials the preparation of carbon nano-materials by chemical vapor deposition method (CVD)—which is one of the most common preparation methods—and reaction simulation. A major factor affecting the material structure is its preparation link. Different preparation methods or different conditions will have a great impact on the structure and properties of the material (mechanical properties, electrical properties, magnetism, etc.). The main influencing factors (precursor, substrate, and catalyst) of carbon nano-materials prepared by CVD are summarized. Through simulation, the reaction can be optimized and the growth mode of substances can be controlled. Currently, numerical simulations of the CVD process can be utilized in two ways: changing the CVD reactor structure and observing CVD chemical reactions. Therefore, the development and research status of computational fluid dynamics (CFD) for CVD are summarized, as is the potential of combining experimental studies and numerical simulations to achieve and optimize controllable carbon nano-materials growth.

In this work, a numerical simulation study on the mixing characteristics of multiphase flow in an autoclave was carried out using CFD technology. The Eulerian–Eulerian model and discrete phase model (DPM) were employed to investigate the solid holdup, critical suspension speed, nonuniformity of solid suspension, gas holdup distribution, bubble tracks, and residence time during stirring leaching in the autoclave. Experiments validate the accuracy of the numerical model, and the experimental values correspond well with the simulation results. The numerical simulation results show that the solid–liquid mixing is mainly affected by the axial flow, the best agitation speed is 400 rpm, and increasing the speed further cannot make the mixture more homogenous and buildup occurred above the autoclave. The calculated critical suspension speed is 406 rpm, which is slightly lower than that obtained from the empirical formula. The gas phase is mainly concentrated in the vortex area above the blade. When the gas phase is in a completely dispersed state (N = 300 rpm), the average residence time of the bubbles is 5.66 s.

Designing high-performance materials for the detection or removal of toxic decomposition gases of sulfur hexafluoride is crucial for both environmental monitoring and human health preservation. Based on first-principles calculations, the adsorption performance and gas-sensing properties of unsubstituted phthalocyanine (H₂Pc) and H₂Pc doped with 4d transition metal atoms (TM = Tc and Ru) towards five characteristic decomposition components (HF, H₂S, SO₂, SOF₂, and SO₂F₂) were simulated. The findings indicate that both the TcPc and RuPc monolayers are thermodynamically and dynamically stable. The analysis of the adsorption energy indicates that H₂S, SO₂, SOF₂, and SO₂F₂ underwent chemisorption on the TcPc monolayer. Conversely, the HF molecules were physisorbed through interactions with H atoms. The chemical adsorption of H₂S, SO₂, and SOF₂ occurred on the RuPc monolayer, while the physical adsorption of HF and SO₂F₂ molecules was observed. Moreover, the microcosmic mechanism of the gas–adsorbent interaction was elucidated by analyzing the charge density differences, electron density distributions, Hirshfeld charges, and density of states. The TcPc and RuPc monolayers exhibited excellent sensitivity towards H₂S, SO₂, and SOF₂, as evidenced by the substantial alterations in the band gaps and work functions of the TcPc and RuPc nanosheets. Our calculations hold significant value for exploring the potential chemical sensing applications of TcPc and RuPc monolayers in gas sensing, with a specific focus on detecting sulfur hexafluoride.

Chemical vapor deposition (CVD) has become an important method for growing graphene on copper substrates in order to obtain graphene samples of high quality and density. This paper mainly focuses on the fluid flow and transmission phenomenon in the reactor under different process operating conditions and reactor structures. Two macroscopic physical parameters that are established as important for CVD growth are temperature and pressure. Based on the special structure of a miniature T45-R Tesla valve acting as a CVD reactor structure, this study uses numerical simulation to determine the effect of the pressure field inside a Tesla valve on graphene synthesis and temperature variation on the graphene surface deposition rate. This macroscopic numerical modeling was compared to the existing straight tube model and found to improve the graphene surface deposition rate by two orders of magnitude when the 1290–1310 K reaction temperature range inside the Tesla valve was maintained and verified through the experiment. This study provides a reference basis for optimizing the reactor geometry design and the effects of changing the operating parameters on carbon deposition rates during a CVD reaction, and will furthermore benefit future research on the preparation of high-quality, large-area, and high-density graphene by CVD.

In the process of the comprehensive recovery and utilization of discarded lithium-ion batteries via acid leaching, a large number of NiS and CoS mixed materials are produced. To improve the metal recovery rate, the kinetics and rate-determining step of the oxygen-rich pressurized acid leaching of Ni and Co were investigated. The results showed that the leaching rates of Ni and Co were greater than 99% under the following conditions: sulfuric acid (leaching agent) concentration of 95 g/L, liquid-to-solid ratio of 6:1, leaching time of 120 min, temperature of 110 °C, stirring speed of 400 r/min, 90% oxygen-rich atmosphere, and pressure of 1.2 MPa. The leaching of Ni and Co was described by the shrinking unreacted core model, and the leaching rates of Ni and Co conformed to the kinetic equation 1 − (1 − x)^1/3 = k·t. The apparent activation energies of the Ni and Co leaching reactions were 50.87 and 45.6 kJ/mol, respectively, and the leaching process was found to be controlled by the chemical reaction at the interface.