Small Band Gap Research Articles

Engineered Sn-TiO2@SnO2 and SnO2@Sn-TiO2 heterophotocatalysts for enhanced As(III) remediation: A comprehensive bulk and surface characterization and precise photocatalytic oxidation rates determination

Arsenite, As(III), is a highly toxic form of arsenic that poses a significant risk to human health if present in drinking water. Oxidation of As(III) to the less toxic As(V) using TiO2 as photocatalyst is an attractive solution in water treatment applications but challenged the high bandgap energy. In this study, we investigate the potential of doping TiO2 with Sn to reduce the bandgap and hence to improve the photocatalytic oxidation (PCO). To this end, we studied first the effect of varying Sn:TiO2 molar doping on the structure of the newly synthesized SnO2@TiO2 and Sn-TiO2@SnO2 hetero photocatalysts. We found that at low Sn:TiO2 doping ratios (0.1Sn:1TiO2), SnO2 tends to float on the surface and form a coat around the TiO2 (SnO2@Sn-TiO2), whereas at higher doping ratio (1Sn:1TiO2) a Sn-TiO2 coat forms alongside SnO2 clusters in the core of the catalyst (Sn-TiO2@SnO2). We assessed the PCO and observed significant shifts to lower conduction and valence band edge energies and a reduction of the bandgap at higher doping ratios. The smallest bandgap was 2.87 eV with a doping ratio of 1Sn:1TiO2. Sn-TiO2@SnO2 and as SnO2@Sn-TiO2 improved the PCO of TiO2 by ∼30 and 46 %, respectively. We finally determined the rate constant (k) for the As(III) oxidation using a combination of spectrochemical and surface sensitive techniques and determined for a 1Sn:1TiO2 (i.e. Sn-TiO2@SnO2) catalyst a value of 0.055 ±0.002 min−1, i.e., 78 folds faster than using only TiO2. We conclude that Sn doping of TiO2 is a very promising approach for improving the PCO of As(III) in water treatment.

(Invited) Microwave-Assisted Synthesis and Characterization of Doped Ge Nanocrystals

Ge is one of the quintessential semiconductors being considered in nanoform for optoelectronic applications. As a group 14 semiconductor, bulk Ge has a small bandgap and a large Bohr exciton radius, making it an attractive semiconductor for various applications, including solar cell technology, photodetectors, and integrated flash memory devices. I will present our work on doped and alloyed Ge nanoparticles via microwave-assisted synthesis and galvanic replacement. I will present new insights from this chemical route that may impact the nanoparticle synthesis of other covalently bonding semiconductors.

Emerging Roles of Graphitic Carbon Nitride-based Materials in Biomedical Applications.

Graphite carbon nitride (g-C3N4) is a two-dimensional conjugated polymer with a unique energy band structure similar to graphene. Due to its outstanding analytical advantages, such as relatively small band gap (2.7 eV), low-cost synthesis, high thermal stability, excellent photocatalytic ability, and good biocompatibility, g-C3N4 has attracted the interest of researchers and industry, especially in the medical field. This paper summarizes the latest research on g-C3N4-based composites in various biomedical applications, including therapy, diagnostic imaging, biosensors, antibacterial, and wearable devices. In addition, the application prospects and possible challenges of g-C3N4 in nanomedicine are also discussed in detail. This review is expected to inspire emerging biomedical applications based on g-C3N4.

The interaction of light with oxygen-vacancy-rich W18O49 nanoparticles synthesized using different acid molarities for acidic and neutral water treatments

Toxic industrial compounds as a global difficulty can adversely impact people's health and the environment which motivates studies on the interaction of light and metal oxide nanoparticles to treat the water through adsorption or photocatalysis mechanism by nanoparticles. In the paper, oxygen-vacancy-rich W18O49 nanorods are successfully synthesized by a facile one-pot hydrothermal method using different molarities of hydrochloric acid (HCl) (2–12 M) as proposed candidates to treat the wastewater and solve the global difficulty related to treating the acidic water. The results declare that the change in acid molarity leads to noteworthy changes in the characteristic properties of the produced W18O49 nanorods, and the lowest acid molarity (2 M) causes the formation of uniform and pure monoclinic W18O49 nanorods with the high specific surface area (SSA) of 51.33 m2/g. Furthermore, the nanorods exhibit indirect and direct band gap energies in the range of 2.52–2.68 eV and 2.54–3.08 eV, respectively, as influenced by varying acid molarities (2–12 M). Furthermore, the impressive effects of acid molarity on the methylene blue removal efficiency of the nanorods under ultraviolet (UV) light are observed. The highest efficiency is obtained for W18O49 nanorods synthesized using the acid molarity of 2 M which can be explained by its high SSA, small band gap energy, generation of a large number of electron-hole pairs, and its efficient charge separation. The efficiencies of water treatment reach up to 99 % and 99.5 % at pH of 7 and 5, respectively, which is an excellent achievement and leads to proposing the mentioned W18O49 nanorods as an excellent candidate for treating wastewater and acid factory effluent which represents an appreciable breakthrough in addressing the issue.

Tailoring body center tetragonal allotropes Cx (x = 8, 12, 16, 20) with C(sp3) and hybrid C(sp3)/C(sp2): Crystal chemistry and ab initio investigations of the physical properties

Based on literature tetragonal ths topology C8 characterized by trigonal C(sp2), selective insertions of carbon induce large structural changes leading to C(sp3) C12 with dia topology after geometry optimizations to ground state structure using calculations within the quantum density functional theory DFT. Further crystal engineering operated on C12 lead to complete the series with novel C16 and C20. Such allotropes respectively characterized by ene (C=C) and propadiene (C=C=C) -like units beside C4 tetrahedra reveal hybrid C(sp3)/C(sp2) with complex stc topology. Alike ths C8, all three allotropes (C12, C16, and C20) identified in high symmetry I41/amd (No. 141) space group are cohesive with larger magnitude for C12 than for ths C8 and close energies for C16 and C20. Mechanical properties show diamond-like Vickers hardness HV for C12 (HV = 95 GPa) and smaller magnitudes for mixed C(sp3)/C(sp2) C16 (HV = 26 GPa) and C20 (HV = 47 GPa), noting that C8 with C(sp2) was found with the largest compressibility with HV = 19 GPa. Dynamically, all allotropes are stable from positive phonon acoustic and optic frequencies with the largest frequency magnitudes for C16 and C20 corresponding to CC and C=C=C vibrations respectively. Thermodynamically, the temperature changes of the specific heat CV show close agreement with diamond experimental values for C12 and larger magnitudes for the three other allotropes. Electronic band structure analyses reveal conductive C8 and C16, insulating C12 with a large band gap close to diamond's and semi-conducting C20 with small band gap.

Activation of peroxymonosulfate under visible-light illumination for enhanced degradation of acetaminophen by self-assembly iron phosphorus/hexagonal tubular graphite carbon nitride

Improving the visible light response by sulfate-based advanced oxidation processes (S-AOPs) is a promising method for the efficient degradation of organic matter in water. Herein, we facilely fabricated the iron phosphorus/hexagonal tubular graphite carbon nitride (FeP/HTCN) composites via two-phase hydrothermal supramolecular self-assembly and thermal-condensation method. FeP/HTCN with the shape of hollow hexagonal tubular loaded iron phosphorus particles was first synthesized. The results suggested that the loading of iron phosphate greatly enhanced its ability to activate peroxymonosulfate (PMS) while also improving the photocatalytic ability of the catalyst due to its smaller bandgap. The combined effect of iron phosphate, HTCN, and visible light (wavelength ≥ 420 nm) assistance facilitated the enhancement of the reaction activity. Electron paramagnetic resonance techniques (EPR) and radial quenching experiments validated that singlet oxygen (1O2) derived from superoxide was the main active species. The degradation pathways of acetaminophen (APAP) were determined and the mechanism of mineralization and decomposition was demonstrated. This work provided a proposal for the application of iron salts represented by iron phosphate in S-AOPs.

Infrared radiation and thermophysical properties of small band gap Cu-doped SrZrO3 perovskite ceramic

High infrared radiation materials have crucial applications in energy saving, heat conversion, and heat dissipation. SrZrO3 (SZO) is a potential material for high infrared radiation, however, its infrared emissivity still needs to be improved. To address this, in this study, Sr(Zr0.9375Cu0.0625)O3-δ (SZCO) perovskite ceramic with high infrared emissivity was prepared, and the impact of Cu ion doping on the electronic structure, infrared radiation characteristics, and thermal conductivity of SrZrO3 were explored. The findings reveal that SZO doped with Cu ions markedly decreases its band gap width from 5.658 eV to 1.467 eV. The infrared emissivity of the SZCO ceramic, sintered at 1200 °C, increases by 28 % in the 3–5 μm band compared to SZO at room temperature. This emissivity positively correlates with temperature, reaching up to 0.95 at 600 °C. The emissivities of SZCO are greater than that of SZO in the 8–14 μm and 1–22 μm band ranges over the test temperature range from room temperature to 600 °C, and both increase with increasing temperature, reaching 0.978 and 0.946 at 600 °C, respectively. Furthermore, the SZCO ceramic demonstrates thermal conductivities ranging from 1.90 to 3.2 W m−1 K−1 below 1400 °C. These results highlight the potential of Sr(Zr0.9375Cu0.0625)O3-δ ceramic as a high infrared radiation material.

Visible light-responsive TiO2-based hybrid nanofiller reinforced multifunctional chitosan film for effective fruit preservation

In this study, we developed a multifunctional chitosan film with visible light-responsive photocatalytic properties by incorporating a novel nanofiller—a nanohybrid particle of poly(tannic acid) (PTA) and TiO2 (TP-NPs). Firstly, the hybridization of TiO2 with PTA not only improved its dispersion but also obtained TP-NPs with smaller band gaps (from 3.11 eV to 1.55 eV) and higher separation efficiency of photogenerated e−-h+ (about 1.5-fold enhancement), thereby producing more reactive oxygen species and enhancing the antibacterial efficacy (compared with TiO2, the antibacterial effect of TP-NPs on Staphylococcus aureus and Escherichia coli was heightened by about 2 times under visible light for 1 h). Secondly, TP-NPs were hydrogen bonded with chitosan, strengthening its mechanical and barrier properties, while imparting exceptional antibacterial efficacy. Moreover, the multifunctional properties enabled the active film to effectively delay the quality deterioration of grapes and kiwifruit. Hence, this study presented a multifunctional active packaging film tailored for fruit preservation.

Unraveling the mystery of sandwich structure: Emerging photocatalytic hydrogen production by g-C3N5 coupled Nb2C MXene forming Schottky heterojunction

The development of new photocatalysts and photocatalytic systems is the essence of the development of photocatalytic hydrogen production engineering. Nitrogen-rich graphite carbon nitride (g-C3N5) has gradually replaced conventional graphite phase carbon nitride (g-C3N4) with a smaller bandgap and high-efficiency visible light utilization. In this study, g-C3N5 and Nb2C MXene coupled composition with sandwich structure were manufactured by a simple ultrasonic magnetic stirring method and used for photocatalytic hydrogen production. By adjusting the ratios of single components in the system, the hydrogen production rate of the optimal sample 4:1g-C3N5/Nb2C under visible light irradiation is 2529.5 μmol·g−1·h−1, which is 21 times higher than that of g-C3N5. The high apparent quantum yield (AQY) value of 17.3 % also proves a high light utilization rate. The atomic force microscopy (AFM) technique reveals variations in the thickness of the samples, while strongly demonstrating the formation of sandwich structure. In addition, X-ray photoelectron spectroscopy (XPS) analysis further reveals the electron transfer paths within the system, preliminarily verifying the formation of Schottky heterojunctions. Kelvin probe force microscopy (KPFM) tests not only re-validate the correctness of the electron transfer path but also demonstrate the accuracy of the energy bands. The density-functional theory (DFT) calculations corroborate that Nb2C MXene plays the role of a photoco-catalyst to form Schottky heterojunctions with g-C3N5 for efficient carrier separation and migration. This work highlights the key role of sandwich structure photocatalytic systems on photocatalytic performance.

Diamond/cubic boron nitride (111) heterojunction interface: Rational regulation of high two-dimonsional electron gas

Wide-bandgap diamond exhibits excellent physical and chemical properties, making it an ideal substrate material for developing high-temperature and high-power semiconductor devices and broadening its application prospects in the field of microelectronics and optoelectronic devices. However, because of the Fermi pinning effect, it is difficult to achieve n-type diamond with excellent transport properties. Cubic boron nitride (cBN) has similar structural properties and a smaller lattice mismatch with diamond. Thus, making the two-dimensional electron gas of the diamond/cBN heterojunction provides a new idea to solve the problem of diamond n-incorporation difficulty and small bandgap regulation range. The diamond/cBN heterojunction is applied to study the law of influence factors on the heterojunction band structure, band alignment, and polarization strength. Further, a regulation mechanism for two-dimensional electron gas density is established at heterojunction interfaces, which can help solve the core difficulties of diamond n-type doping, small bandgap regulation range, and high impedance, providing a theoretical basis for realizing diamond power devices with high power density and low power consumption.

Controlling the Phase Distribution of Single Bromide Quasi-2-Dimensional Perovskite Crystals via Solvent Engineering for Pure-Blue Light-Emitting Diodes.

To achieve pure-blue emission (460-470 nm), we manipulate the crystallization process of the quasi-2D perovskite, (PBA)2Csn-1PbnBr3n+1, prepared by a solution process. The strategy involves controlling the distribution of "n" phases with different bandgaps, solely utilizing changes in the precursor's supersaturation to ensure that the desired emission aligns with the smallest bandgap. Adjustments in photoluminescence (PL) wavelength are made by changing the solute concentration and solvent polarity, as these factors heavily influence the diffusion of cations, a crucial determinant for the value of "n". Subsequently, we enhance the PL quantum yield from 31 to 51% at 461 nm using trioctylphosphine oxide (TOPO) as an additive of antisolvent, which passivates halide vacancy and promotes orderly crystal growth, leading to faster carrier transfer between phases. With these strategies, we successfully demonstrate pure-blue LEDs with a turn-on voltage of 3.3 V and an external quantum efficiency of 5.5% at an emission peak of 470 nm with a full-width at half-maximum of 31 nm.

Synergistic charge-transfer dynamics of rigid fused and unfused backbone with donors lead to promising photovoltaic properties of diazaborinine-based chromophores

Herein, a series of diazaborinin based derivatives (FABD1–FABD8) having D-π-D configuration was designed by inserting different types of rigid fused and unfused π-bridges into reference molecule (FABR) to explore their photovoltaic characteristics. To determine the optoelectronic and charge transport characteristics of these analogues, DFT/TD-DFT based calculations were conducted at the MPW1PW91/6-31G (d,p) level. For this, various analyses were performed such as transition density matrix (TDM), global reactivity parameters (GRP), open-circuit voltage (Voc), optical properties (UV–Vis), binding energy (Eb), hole-electron and frontier molecular orbital (FMO) energies. Their insights indicate that a rigid fused π-bridge greatly lowers the band gap as compared to an unfused π-spacers. Particularly, FABD7 showed the lowest energy gap of 2.20 eV owing to the presence of a rigid fused central core as compared to FABR with a band gap of 2.65 eV. Similarly, the entitled designed derivatives demonstrated a redshift absorption in the range of 585.7–704.6 nm while FABR is reported with 558.7 nm in the solvent phase. Furthermore, these derivatives displayed significant Voc with blending of PC61BM acceptor. This observation was also supported by DOS and TDM based insights. Interestingly, FABD7 seemed as a viable photovoltaic material due to its strong optical properties and small band gaps. These results uncover that the designed chromophores may be considered as efficient to enhance the performance of OSCs.

Energy band engineering of graphitic carbon nitride for photocatalytic hydrogen peroxide production

AbstractHydrogen peroxide (H2O2) is one of the 100 most important chemicals in the world with high energy density and environmental friendliness. Compared with anthraquinone oxidation, direct synthesis of H2O2 with hydrogen (H2) and oxygen (O2), and electrochemical methods, photocatalysis has the characteristics of low energy consumption, easy operation and less pollution, and broad application prospects in H2O2 generation. Various photocatalysts, such as titanium dioxide (TiO2), graphitic carbon nitride (g‐C3N4), metal‐organic materials, and nonmetallic materials, have been studied for H2O2 production. Among them, g‐C3N4 materials, which are simple to synthesize and functionalize, have attracted wide attention. The electronic band structure of g‐C3N4 shows a bandgap of 2.77 eV, a valence band maximum of 1.44 V, and a conduction band minimum of −1.33 V, which theoretically meets the requirements for hydrogen peroxide production. In comparison to semiconductor materials like TiO2 (3.2 eV), this material has a smaller bandgap, which results in a more efficient response to visible light. However, the photocatalytic activity of g‐C3N4 and the yield of H2O2 were severely inhibited by the electron‐hole pair with high recombination rate, low utilization rate of visible light, and poor selectivity of products. Although previous reviews also presented various strategies to improve photocatalytic H2O2 production, they did not systematically elaborate the inherent relationship between the control strategies and their energy band structure. From this point of view, this article focuses on energy band engineering and reviews the latest research progress of g‐C3N4 photocatalytic H2O2 production. On this basis, a strategy to improve the H2O2 production by g‐C3N4 photocatalysis is proposed through morphology control, crystallinity and defect, and doping, combined with other materials and other strategies. Finally, the challenges and prospects of industrialization of g‐C3N4 photocatalytic H2O2 production are discussed and envisioned.

Defect Engineering of MoTe2 via Thiol Treatment for Type III van der Waals Heterojunction Phototransistor.

Molybdenum ditelluride (MoTe2) nanosheets have displayed intriguing physicochemical properties and opto-electric characteristics as a result of their tunable and small band gap (Eg ∼ 1 eV), facilitating concurrent electron and hole transport. Despite the numerous efforts devoted to the development of p-type MoTe2 field-effect transistors (FETs), the presence of tellurium (Te) point vacancies has caused serious reliability issues. Here, we overcome this major limitation by treating the MoTe2 surface with thiolated molecules to heal Te vacancies. Comprehensive materials and electrical characterizations provided unambiguous evidence for the efficient chemisorption of butanethiol. Our thiol-treated MoTe2 FET exhibited a 10-fold increase in hole current and a positive threshold voltage shift of 25 V, indicative of efficient hole carrier doping. We demonstrated that our powerful molecular engineering strategy can be extended to the controlled formation of van der Waals heterostructures by developing an n-SnS2/thiol-MoTe2 junction FET (thiol-JFET). Notably, the thiol-JFET exhibited a significant negative photoresponse with a responsivity of 50 A W-1 and a fast response time of 80 ms based on band-to-band tunneling. More interestingly, the thiol-JFET displayed a gate tunable trimodal photodetection comprising two photoactive modes (positive and negative photoresponse) and one photoinactive mode. These findings underscore the potential of molecular engineering approaches in enhancing the performance and functionality of MoTe2-based nanodevices as key components in advanced 2D-based optoelectronics.

Spin–Orbit Coupling Free Nonlinear Spin Hall Effect in a Triangle-Unit Collinear Antiferromagnet with Magnetic Toroidal Dipole

We investigate emergent conductive phenomena triggered by collinear antiferromagnetic orderings. We show that an up-down-zero spin configuration in a triangle cluster leads to linear and nonlinear spin conductivities even without the relativistic spin–orbit coupling; the linear spin conductivity is Drude-type, while the nonlinear spin conductivity has Hall-type characterization. We demonstrate the emergence of both spin conductivities in a breathing kagome system consisting of a triangle cluster. The nonlinear spin conductivity becomes larger than the linear one when the Fermi level lies near the region where a small partial band gap opens. Our results indicate that collinear antiferromagnets with triangular geometry give rise to rich spin conductive phenomena.

Band engineering for building cascading charge transport channels in ternary CdS-based nanorod array photoanode toward efficient photoelectrochemical H2 generation

A novel CdS/CdSe/Cu2O nanorod array (NRA) photoelectrode with cascading charge transport channels was designed for the first time to remarkedly boot photoelectrochemical (PEC) hydrogen generation under visible light illumination with zero bias. This ternary photoelectrode was constructed by modifying CdS nanorod arrays with n-type CdSe and p-type Cu2O nanoparticles, successively. In this novel photoanode, CdSe and Cu2O with small band gap not merely highly heighten the visible light absorption capacity of CdS, but more importantly integrate with CdS to build cascading charge transport channels at the CdS/CdSe and CdSe/Cu2O interfaces, dramatically facilitating the separation and transport efficiency for photoexcited electron and hole pairs. The CdS/CdSe/Cu2O NRA photoelectrode gains an obvious hydrogen generation rate of 193.2 μmol·h−1, 8.2 times higher than that of bare CdS NRA photoelectrode. The remarkably enhanced PEC hydrogen production for the CdS/CdSe/Cu2O NRA photoanode can be ascribed to effective solar energy utilization and charge carrier separation.

Tuning the structural, optical, and dielectric properties of europium-doped barium titanate ceramics

This study explores the optical and dielectric properties of pure and europium-doped barium titanate ceramics with formula Ba1−3x/2EuxTiO3 (x=0,0.005,0.015and0.025\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$x=0,0.005, 0.015\ ext{ and }0.025$$\\end{document}). The materials were synthesized using the solid-state reaction method. The influence of Eu + 3 ion incorporation on the crystal structure was examined using XRD, which indicated the formation of a cubic phase. Lattice parameter measurements showed excellent agreement with various theoretical models for predicting the lattice constant, with an average error of only 0.20%. UV–visible spectroscopy analysis is utilized to investigate optical characteristics, revealing a decrease in the optical band gap from 2.65 to 2.77 eV post-Eu doping, which is notably lower than the bulk barium titanate value of 3.2 eV. Materials with smaller band gaps are more suited for optoelectronic applications like photodetectors and light-emitting diodes (LEDs). The dielectric response of europium-doped barium titanate was studied across a frequency range of 1 kHz to 2 MHz and a temperature range of 77 to 300 K, showing remarkable stability. The frequency-dependent dielectric analysis revealed that the dielectric constant initially increased with increasing doping concentration, but decreased at higher concentrations. These results suggest that europium-doped barium titanate holds significant promise for future electronic device applications due to its enhanced optical and dielectric properties.

Impact on preferred orientation and crystal strain behavior of nanocrystal anatase-TiO2 by X-ray diffraction technique

The primary goal of this research outline is the conversion of titanium isopropoxide (TTIP) at 50.0 °C to form a high crystalline preferred oriented predominant (101) with a low crystal strain of 90.0 % anatase-TiO2 phase. With the interval of time, the peptizing agent (IP) reacts to an acidic aqueous medium and preferential growth of anatase-TiO2 has been identified. Exhaustive recombination in X-ray diffraction (XRD) analysis ensures the crystal strain, lattice volume, lattice parameters, d-spacing and crystallite size. UV–vis-NIR showed maximum absorption of 320.0 nm with 0.78 a.u. at blue shift for decreasing nano-size and smaller bandgap 3.0313 eV of larger dimensions anatase-TiO2. The preferred orientation also revealed by nanobeam diffraction (NBD) of TEM enables qualitative lattice type and highly crystal orientated predominant (101) plane 5.60 nm−1 in a diffraction pattern imposed on 200.0 kv parallel electron bean from LaB6 filament.

Amplifying Photochromic Response in Tungsten Oxide Films with Titanium Oxide and Polyvinylpyrrolidone.

Tungsten oxide (WO3) is known for its photochromic properties, making it useful for smart windows, displays, and sensors. However, its small bandgap leads to rapid recombination of electron-hole pairs, resulting in poor photochromic performance. This study aims to enhance the photochromic properties of WO3 by synthesizing hexagonal tungsten oxide via hydrothermal synthesis, which increases surface area and internal hydrates. Titanium oxide (TiO2) was adsorbed onto the tungsten oxide to inject additional charges and reduce electron-hole recombination. Additionally, polyvinylpyrrolidone (PVP) was used to improve dispersion in organic solvents, allowing for the fabrication of high-quality films using the doctor blade method. Characterization confirmed the enhanced surface area, crystal structure, and dispersion stability. Reflectance and transmittance measurements demonstrated significant improvements in photochromic properties due to the composite structure. These findings suggest that the introduction of TiO2 and PVP to tungsten oxide effectively enhances its photochromic performance, broadening its applicability in various advanced photochromic applications.

Synthesis of sub‐micron sized SiC particles with high defect density by using polytetrafluoroethylene as an additive

AbstractA new preparation process for silicon carbide (SiC) powder is developed. In the Si–(C) –PTFE–Ar system, the grain size and morphology of the product 3C–SiC were controlled by adding a carbon source (graphite) and changing the percentage of polytetrafluoroethylene (PTFE) (0%, 10%, and 20%). The experimental results showed that the SiC powders prepared using a molar ratio of 1:1 silicon powder to graphite, plus 20% PTFE have a uniform particle size distribution (∼130 nm), a lamellar structure made of spherical particle stacking, a small bandgap (1.80 eV), a high carrier concentration, and a large number of lattice defects. These properties are expected to increase the electrical conductivity of 3C–SiC and decrease its thermal conductivity, thus providing a promising feedstock preparation option for SiC thermoelectric materials. In addition, the mechanism of PTFE in the preparation of SiC reactions was studied in detail.