Sulfur Doping Research Articles

硫掺杂对析氧反应催化剂表面重构的影响

硫掺杂对析氧反应催化剂表面重构的影响

Improving stability and reversibility of manganese dioxide cathode materials via nitrogen and sulfur doping for aqueous zinc ion batteries

Manganese based oxides are one of the most promising cathode materials for secondary aqueous zinc ion batteries. However, its structural instability and slow reaction kinetics have hampered its large-scale application. Here, a rational nitrogen and sulfur diatomic doping strategy is suggested to enhance the electrochemical activity and reversibility of manganese dioxide. The nitrogen and sulfur-doped manganese dioxide (N-MnxOy-S) electrode material is synthesized by a simple hydrothermal approach combined with a low temperature vulcanization treatment. The electrode exhibits an excellent initial discharge capacity of 178 mA h g−1 at 1 A g−1. Even at a high rate of 2 A g−1, the capacity retention rate exceeds 90% for 3000 cycles. The large number of oxygen defects increases the storage sites for zinc ions, resulting in the excellent electrochemical properties of N-MnxOy-S. Additionally, the Mn-S and Mn-N bonds in N-MnxOy-S boost the interfacial dynamics of manganese dioxide, which can effectively reduce the dissolution of manganese and efficiently improve the electronic conductivity. The current study demonstrates that nitrogen and sulfur co-doping is a successful method for enhancing the electrochemical performance of manganese-based oxide cathodes, which serves as an important benchmark for the development of cathode materials appropriate for aqueous zinc ion batteries.

Dual Integrating Oxygen and Sulphur on Surface of CoTe Nanorods Triggers Enhanced Oxygen Evolution Reaction.

The bottleneck of large-scale implementation of electrocatalytic water-splitting technology lies in lacking inexpensive, efficient, and durable catalysts to accelerate the sluggish oxygen evolution reaction kinetics. Owing to more metallic features, transition metal telluride (TMT) with good electronic conductivity holds promising potential as an ideal type of electrocatalysts for oxygen evolution reaction (OER), whereas most TMTs reported up to now still show unsatisfactory OER performance that is far below corresponding sulfide and selenide counterparts. Here, the activation and stabilization of cobalt telluride (CoTe) nanoarrays toward OER through dual integration of sulfur (S) doping and surface oxidization is reported. The as-synthesized CoO@S-CoTe catalyst exhibits a low overpotential of only 246mV at 10mAcm-2 and a long-term stability of more than 36h, outperforming commercial RuO2 and other reported telluride-based OER catalysts. The combined experimental and theoretical results reveal that the enhanced OER performance stems from increased active sites exposure, improved charge transfer ability, and optimized electronic state. This work will provide a valuable guidance to release the catalytic potential of telluride-based OER catalysts via interface modulating engineering.

Regulating Electronic Structure of Fe–N4 Single Atomic Catalyst via Neighboring Sulfur Doping for High Performance Lithium–Sulfur Batteries

AbstractConstructing high performance electrocatalysts for lithium polysulfides (LiPSs) adsorption and fast conversion is the effective way to boost practical energy density and cycle life of rechargeable lithium–sulfur (Li–S) batteries, which have been regarded as the most promising next generation high energy density battery but still suffering from LiPSs shuttle effect and slow sulfur redox kinetics. Herein, a single atomic catalyst of Fe–N4 moiety doping periphery with S (Fe–NSC) is theoretically and experimentally demonstrated to enhance LiPSs adsorption and facilitated sulfur conversion, due to more charge density accumulated around Fe–NSC configuration relative to bare Fe–N4 moiety. Thereafter, the graphene oxide supported Fe–NSC catalyst (Fe–NSC@GO) is modified to the commercial separator through a simple slurry casting method. Thus, Li–S cells with Fe–NSC@GO modified separators display high discharge capacity and excellent cyclability, showing 1156 mAh g−1 at 1 C rate and a low capacity decay of only 0.022% per cycle over 1000 cycles. Even with a high sulfur loading of 5.1 mg cm−2, the cell still delivers excellent cycling stability. This work provides a fresh insight into electrocatalyst structural tuning to improve the electrochemical performance of Li–S batteries.

Synergistic effects of holey nanosheet and sulfur-doping on the photocatalytic activity of carbon nitride towards NO removal

Photocatalysis provides a sustainable way for NOx elimination. However, efficient and safe photocatalytic removal of NOx remain a great challenge due to the limited light-harvesting ability and quick recombination of charge carriers. Herein, holey sulfur-doped g-C3N4 nanosheets (CNN–S) was reported by directly calcining a mixture of hydrolyzed dicyandiamide and thioacetamide. The specific surface area of the pristine g-C3N4 nanosheets (CNN–S0) is 3–4 times higher than bulk g-C3N4 (BCN), and the photocatalytic NO removal rate also increased from 17% (BCN) to 35% (CNN–S0). The effect of sulfur content on the photocatalytic performance was systematic studied, and CNN–S0.5 sample exhibits the highest NO removal rate (53%). The high photoreactivity of S-doped g-C3N4 nanosheets can be attributed to enhanced visible light absorption, increased specific surface area, and effective separation and transfer of photo-generated charges owing to the synergistic effect of the nanosheet structure and sulfur doping. In addition, density functional theory calculations show that the doping of S is also beneficial to the adsorption and activation of the reactants on CN.

Comparative Study on Enhanced Photocatalytic Activity of Visible Light-Active Nanostructures for Degradation of Oxytetracycline and COD Removal of Licorice Extraction Plant Wastewater

This study evaluates the effects of carbon, nitrogen, and sulfur dopants on the photocatalytic activity of TiO2 for degradation of oxytetracycline (OTC) and chemical oxygen demand (COD) removal from licorice extraction plant wastewater (LEPW). Three novel visible-light-responsive nanostructures, including L-Histidine-TiO2, L-Methionine-TiO2 and L-Asparagine-TiO2, were successfully synthesized. The results showed that the modification of TiO2 with these three amino acids made the catalyst active in the visible light region and reduced the recombination rate of e−/h+ pairs according to PL analysis. The photodegradation efficiency of L-Histidine (2 wt.%)-TiO2 was 100% and 94% for OTC and COD, respectively. It showed the highest photocatalytic activity under illumination, compared to L-Methionine (1.5 wt.%)-TiO2 and L-Asparagine (2 wt.%)-TiO2. Synthesized composites were characterized with SEM, XRD, FTIR, DRS, and PL analyses. The biological oxygen demand to COD (BOD5/COD) ratio for treated LEPW was determined to be 0.5–0.6, confirming the enhanced biodegradability of the treated effluent. The effect of the independent variables, namely, initial concentration of OTC and COD, catalyst dosage, irradiation time, pH of solution, and light intensity, on the photocatalytic process was evaluated by Response Surface Methodology (RSM), and the optimum value of each independent parameter for maximum degradation of OTC and COD by L-Histidine (2 wt.%)-TiO2 was determined. The radical trapping experiment was performed with various scavengers in order to propose a photocatalytic mechanism, showing that hydroxyl radicals were the main active species. L-Histidine (2 wt.%)-TiO2 showed a stable and reusable structure even after four cycles of COD removal under the following optimal conditions of [COD]: 300 mg/L, [catalyst]: 1 g/L, light intensity: 25 W/cm2 at pH = 4 after 180 min irradiation.

Ultrafast laser heating for controlling the optoelectronic properties of sulfur hyperdoped black silicon

Ultrashort pulse laser processed sulfur hyperdoped black silicon represents a promising silicon-based material for infrared optoelectronic applications due to its high sub-bandgap optical absorptance. Non-thermal melting and resolidification processes associated with such laser processing, however, result in amorphous and polycrystalline phases which may be detrimental for this purpose. Furthermore, the sulfur impurities are electrically inactive, impeding the formation of a rectifying junction. This work demonstrates an ultrafast laser heating process based on heat accumulation with laser pulses of 10 ps pulse duration at high repetition rates of 41 MHz and peak fluences between 33% and 66% of the ablation threshold as a method to (i) recrystallize the material and (ii) electrically activate the sulfur dopants while (iii) maintaining the sub-bandgap absorption. Furthermore, laser heating recovers the optical activity of sulfur states that have been previously deactivated by thermal annealing. The demonstrated process can have versatile applications in material functionalization due to its highly localized heat input accompanied by high cooling rates.

Improved photoactivity of TiO2 photoanode of dye-sensitized solar cells by sulfur doping

The photoactivity of the photoanode determines the power conversion efficiency of dye-sensitized solar cells (DSSC). TiO2 has come up as a potential photoanode in DSSC but it has several drawbacks, including large trap density due to lattice defect that influences carrier transport, interfacial charge transfer, and carrier transport. Here we present an effective approach to improve the TiO2 photoanode photoelectrical properties by chalcogenide ion doping, i.e. sulfur (S), that compensates the oxygen vacancy in the TiO2 lattice, enhancing the photoactivity at the visible region, reducing trap density and increasing the photovoltaic process in DSSC device. S doping in the TiO2 lattice was achieved by thiourea treatment. Our result shows that the S doping improves the interfacial charge transfer and reduced the trap density, improving the carrier lifetime and power conversion efficiency. The champion device, S-doped TiO2 with 0.3 M thiourea treatment, produces the DSSC with power conversion efficiency as high as 4.56%, which is two times higher than the DSSC using pristine TiO2. The S doping should find a potential approach for enhancing the photoactivity of the TiO2 photoanode of the DSSC device.

Construction of S-N-C bond for boosting bacteria-killing by synergistic effect of photocatalysis and nanozyme

Bacterial infection-related diseases are major public safety issues leads to millions of deaths annually. Herein, a porous sulfur doped graphitic carbon nitride (g-SCN) for ecofriendly, metal-free and low systemic toxicity were synthesized. Sulfur doping enables to broaden the absorption spectrum and promote the photocarriers separation for photocatalysis enhancement. Moreover, sulfur element will coordinate with nitrogen, changing the electronic state and endowing g-SCN with the property of nanozyme. More importantly, we established different models and confirmed that S-N-C coordination is the source of peroxidase (POD)-like activity through theory and experiment. The increased specific surface area of g-SCN, ascribing to the porous structure, makes it easier to trap bacteria. With the synergistic effect of photocatalysis and nanozyme, the prepared g-SCN has the ability to kill both gram-negative and gram-positive bacterium, with an antibacterial efficiency up to 100%. This work provides innovative synergistic strategy for constructing nanomaterials for highly efficient antibacterial therapy.

Self-Assembled Hierarchical Silkworm-Type Bimetallic Sulfide (NiMo3S4) Nanostructures Developed on S-g-C3N4 Sheets: Promising Electrode Material for Supercapacitors

An electrode material composed of bimetallic sulfides on g-C3N4 typically enhances the energy storage capacity of devices due to the merits of each component, but it still suffers from low energy density over long cycles. Although Ni-based bimetallic sulfides have become good electrode materials for supercapacitors, practical applications of these materials are hindered due to unsatisfactory cycling stability. Here, we demonstrate a simple two-step in situ approach to prepare bimetallic sulfide nanobulbs on a sulfur-doped graphitic carbon nitrate matrix for a NiMo3S4@S-g-C3N4 composite, which is further used for supercapacitor devices. A small amount of sulfur doping to g-C3N4 enhances the conducting channels for electron transportation. An NMS@S-gC nanocomposite clearly shows the formation of small nanobulbs that are formed as silk warm-type hierarchical morphology structures and these were wrapped on the surface of S-gC porous nanosheets. The device made up of these composites exhibited a maximum specific capacitance of 142.4 F g–1, a high energy density of 41.4 Wh kg–1, and a power density of 723.5 W kg–1 at a current density of 1 A g–1. Meanwhile, in a three-electrode device configuration, the working electrode demonstrates a specific capacitance of 934.2 F g–1 at 1 A g–1, which is 1.6 times greater than that of bare NiMo3S4. Moreover, the capacitance retention of the device is about 91% even after 5000 cycles at 8 A g–1. The results obtained in this investigation surpassed most reported metallic sulfides on g-C3N4. Hence, this work could give a different pathway for the synthesis of electrode materials for energy storage devices.

Co,N,S co-doped hollow carbon with efficient oxidase-like activity for the detection of Hg2+ and Fe3+ ions

Most nanozymes have limited catalytic ability, and constructing high performance nanozymes is important and challenging. Metal-carbon hybrid materials obtained by integrating transition metals into carbon can not only generate rich active sites, but also enhance their electrical conductivity. Heteroatom doping is shown to be an efficient strategy to improve the catalytic activity of carbon-based nanozymes. Here, by taking advantage of the structural merits of MOFs-derived porous carbon materials combined with sulfur doping strategy, the Co,N,S co-doped hollow carbon material, i.e. Co-N/S-HCN, was fabricated by pyrolyzing a thiomalic acid (TA) modified zeolitic imidazolate framework (ZIF-67@TA) in a nitrogen atmosphere. It exhibits hollow dodecahedron shape with rich defects, high BET specific surface area of 240.75 m2/g and pore volume of 0.27 cm3/g. The electrochemical characterization reveals the doping of S reduces the charge transfer resistance of the Co-N-HCN, accelerates electron transfer rate, and finally boosts its catalytic activity. The Co-N/S-HCN shows superior oxidase-like activity and can convert colorless 3,3′,5,5′-tetramethylbenzidine (TMB), o-phenylenediamine and 2,2′-azo-bis (3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt into visible color substrates without hydrogen peroxide. The oxidase-like activity of Co-N/S-HCN was 2.1 times that of Co-N-HCN. The quenching trials revealed the generation of O2•−, •OH and 1O2 during catalytic TMB oxidation by Co-N/S-HCN. The Co-N/S-HCN oxidase-like nanozyme exhibited good affinity to TMB with a Km value of 0.25 mM and Vmax of 4.19 × 10−7 M s−1. In terms of Soft-Hard Acid-Base principle, Hg2+ combines easily with the sulfur. Thus, the introduction of Hg2+ ions can restrain TMB oxidation catalyzed by Co-N/S-HCN, thereby inhibiting the color reaction. In addition, the addition of 8-hydroxyquinoline can restrain TMB oxidation catalyzed by Co-N/S-HCN, resulting in a decrease in absorbance at 652 nm. However, the color reaction recovers in the presence of Fe3+, resulting in an increase in absorbance at 652 nm. In terms of above fact, a colorimetric sensing platform for determining Hg2+ and Fe3+ ions was established and successfully used for detecting Hg2+ in water samples and Fe3+ in liquors. This work offers a different way to prepare nanozymes with efficient oxidase-like activity and is of great significance for detecting heavy metal ions in environmental and food samples.

Thiophene-sulfur doping in nitrogen-rich porous carbon enabling high-ICE/rate anode materials for potassium-ion storage

Sulfur doping in carbon materials is generally considered to enhance initial coulombic efficiency, potassium storage capacity and reaction kinetics.

Coordination engineering of atomically dispersed zirconium on graphene for the oxygen reduction reaction.

We study the effect of boron and sulfur doping on graphene with atomically dispersed zirconium as an electrocatalyst for the oxygen reduction reaction (ORR) by using density functional theory (DFT). The use of Zr as a metal center offers a highly stable catalyst due to the high electronegativity difference between Zr and its ligand. The origin of the ORR activity improvement has been investigated thoroughly. Here, we proposed a novel geometric descriptor for an atomically dispersed zirconium on a nitrogen-doped graphene catalyst with an axial oxygen ligand, which is the fractional coordination number of the Zr atom. We found that the fractional coordination number can successfully describe the shift of the dz2 band center in the doped compound, which is related to the binding energy of the Zr to the O ligand. We also found that the oxygen ligand is mobile during the adsorption process of ORR intermediates, and hence it is imperative for the axial oxygen ligand to bind neither too strongly nor too weakly to the Zr atom. The coordination engineering strategy can successfully enhance the ORR activity, shifting the ORR overpotential from 0.75 V and 0.92 V to 0.33 V and 0.32 V. This study provides new insights into the origin of ORR activity by connecting the novel geometric descriptor to the electronic structure and finally it is connected to the ORR activity.

Interfacing NiV layered double hydroxide with sulphur-doped g-C3N4 as a novel electrocatalyst for enhanced hydrogen evolution reaction through Volmer–Heyrovský mechanism

The poor intrinsic catalytic activity of g-C3N4 towards electrochemical hydrogen evolution reaction (HER) was overcome by sulphur doping and NiV LDH compositing. A comprehensive account of enhanced HER through the Volmer–Heyrovský mechanism is provided.

Sulphur-doped carbon particles from almond shells as cheap adsorbent for efficient Cd(II) adsorption

One of the ways to increase the adsorption capacity of carbon-based materials is to add heteroatoms. However, the use of sulphur-doped carbons is quite limited. This study includes the production of activated carbon (AC) from almond shells by microwave heating and KOH chemical agent and sulphur doping by hydrothermal heating treatment of the obtained ACs with sulphuric acid for Cd(II) adsorption. The thermogravimetric/differential thermal analyser (TG-DTA), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and nitrogen adsorption analyses were performed for characterization. For KOH-MA-S, the FTIR spectra peaks associated with the S O stretching vibration appeared at approximately 1153 cm −1 and 1024 cm −1 . The SEM image of the KOH + MA + S sample shows that a heterogeneous and layered structure is formed again due to the collapse or coalescence of the pores with the hydrothermal sulphuric acid activation on the carbonaceous surface. While there is almost no sulphur in the KOH-MA sample, there is approximately 9 % sulphur in the KOH-MA-S sample in the EDS results. The adsorption performance, kinetics, thermodynamics and mechanism for Cd(II) adsorption on sulphur doped ACs were evaluated. The isotherm and kinetic results showed that Cd(II) adsorption on sulphur-doped AC fits the Langmuir isotherm and pseudo-second-order kinetics with high correlation values. The adsorption capacity values (Qm) obtained for Cd(II) adsorption were 282.70 mg/g. • ACs based on almond shells by microwave heating with KOH activation were prepared. • Sulphur doped ACs by hydrothermal sulphuric acid treatment was prepared. • Cd(II) adsorption by sulphur doped AC was carried out. • Qm value for Cd(II) adsorption was 222.38 mg/g. • Adsorption mechanism of Cd(II) on sulphur doped AC was evaluated.

Regulating the coordination environment of Fe/Co–N/S–C to enhance ORR and OER bifunctional performance

Fe/Co–N/Sx–C catalysts with a sulfur dopant are designed and successfully synthesized, and they show excellent ORR and OER bifunctional electrocatalytic performance both theoretically and experimentally.

Preparation and Characterization of Nitrogen and Sulfur Doped Green Carbon Dots with Aggregation-induced Emission

Preparation and Characterization of Nitrogen and Sulfur Doped Green Carbon Dots with Aggregation-induced Emission

Tunable sulphur doping in CuFe2O4 for the efficient removal of arsenic through arsenomolybdate complex adsorption: kinetics, isothermal and mechanistic studies

Arsenic is regarded as a highly toxic element that naturally exists in ground drinking water.

Electronic structures and optical spectra of KDP crystals with Sp doping defects: a first-principles study.

In order to further clarify the effect of sulfur doping on the laser damage threshold of potassium dihydrogen phosphate (KDP), the properties of sulfur substituting for phosphorus doping defects (SP) in KDP crystals with paraelectric (PE) and ferroelectric (PE) phases are studied in this article. More accurate defect transition levels were obtained by band edge correction, and the band edge corrected values were 1.28 eV and 1.88 eV for the PE and FE phases, respectively. The defect formation energies with four different defect charges (0, +1, +2, and-1) were obtained using the finite size correction scheme. The stable defect charge states were (+2 charge state) (+1 charge state) and (-1 charge state) in turn when the Fermi level moved from the valence band maximum (VBM) to the conduction band minimum (CBM). Moreover, by considering the electron-phonon coupling, the optical absorption and emission spectra were obtained. The absorption peak for the state of the PE phase at 4.63 eV was close to the experimental value. We predicted that the absorption peak at 4.50 eV belongs to the state with the FE phase. The emission peaks at 0.10 eV and 1.36 eV were related to the PE and FE phases, accordingly. The absorption may affect the application of S-KDP crystals and reduce the laser damage threshold.

Deep sulfur doping induces the rapid electrochemical self-reconstruction of Ni–Fe hydroxide to drive water oxidation

Low crystallinity and deep sulfur doping effectively facilitate the rapid and favorable electrochemical reconstruction of Ni–Fe hydroxides toward an enhanced OER catalysis.