Sulfur-doped Carbon Nitride Research Articles

Evaluation of a photoelectrochemical platform based on strontium titanate, sulfur doped carbon nitride and palladium nanoparticles for detection of SARS-CoV-2 spike glycoprotein S1

This work aims to develop a photoelectrochemical (PEC) platform for detection of SARS-CoV-2 spike glyprotein S1. The PEC platform is based on the modification of a fluorine-doped tin oxide (FTO) coated glass slide with strontium titanate (SrTiO3 or ST), sulfur-doped carbon nitride (g–C3N4–S or CNS) and palladium nanoparticles entrapped in aluminum hydroxide matrix (PdAlO(OH) or PdNPs). The PEC platform was denoted as PdNPs/CNS/ST/FTO and it was characterized by SEM, TEM, FTIR, DRX, and EIS. The PEC response of the PdNPs/CNS/ST/FTO platform was optimized by evaluating the effects of the concentration of the donor molecule, the nature of the buffer, pH, antibody concentration, potential applied to the working electrode, and incubation time. The optimized PdNPs/CNS/ST/FTO PEC platform was modified with 5 μg mL−1 of antibody for determination of SARS-CoV-2 spike glycoprotein S1. A decrease in the photocurrent was observed with an increase in the concentration of SARS-CoV-2 from 1 fg mL−1 to 1000 pg mL−1 showing that the platform is a promising alternative for the detection of S1 protein from SARS-CoV-2. The designed PEC platform exhibited recovery percentages of 96.20% and 109.65% in artificial saliva samples.

One-step fabrication of mesoporous sulfur-doped carbon nitride for highly selective photocatalytic transformation of native lignin to monophenolic compounds

Photocatalytic selective transform native lignin into valuable chemicals is an attractive but challenging task. Herein, we report a mesoporous sulfur-doped carbon nitride (MSCN-0.5) which is prepared by a facile one-step thermal condensation strategy. It is highly active and selective for the cleavage Cα−Cβ bond in β−O−4 lignin model compound under visible light radiation at room temperature, achieving 99% substrate conversion and 98% Cα−Cβ bond cleavage selectivity. Mechanistic studies revealed that the Cβ−H bond of lignin model compounds activated by holes and generate key Cβ radical intermediates, further induced the Cα−Cβ bond cleavage by superoxide anion radicals (•O2−) to produce aromatic oxygenates. Waste Camellia oleifera shell (WCOS) was taken as a representative to further understand the reaction mechanisms on native lignin. 33.2 mg of monophenolic compounds (Vanillin accounted for 22% and Syringaldehyde for 34%) can be obtained by each gram of WCOS lignin, which is 2.5 times as that of the pristine carbon nitride. The present work offers useful guidance for designing metal-free heterogeneous photocatalysts for Cα−Cβ bond cleavage to harvest monophenolic compounds.

A 3D peony-like sulfur-doped carbon nitride synthesized by self-assembly for efficient photocatalytic hydrogen production

Photocatalytic hydrogen evolution reaction (HER) provides a new way for the development of clean energy. Herein, a high-performance peony-like 3D structure S-doped carbon nitride (SCNx) with a large specific surface area was synthesized through a universal and non-thermal polymerization template-free approach. As an additional component, the introduction of trithiocyanuric acid in the raw material led to the formation of supramolecular intermediates through hydrogen bond self-assembly, and the sulfur was introduced into the framework of g-C3N4 subsequently. The charge separation lifetime of SCNx was studied by transient absorption spectroscopy, and the reason for its excellent optical performance was revealed from a dynamic perspective. Furthermore, the resulting SCNx composite material shows significant photocatalytic hydrogen release performance under visible light irradiation. In particular, the photocatalytic hydrogen rate of SCN1.0 reached 567.7 μmol/h, which was almost 53 times that of BCN, and was also 2.3 times that of SCN0 obtained by the binary self-assembly of melamine and cyanuric acid. Our finding advances the application of simple, environmentally friendly, and scalable strategy for the synthesis of high-performance sulfur-doped g-C3N4 photocatalysts.

Ultrathin sulfur-doped holey carbon nitride nanosheets with superior photocatalytic hydrogen production from water

Surface engineering is an efficient way to enhance photoabsorption, promote charge separation and boost photocatalysis. Herein, sulfur-doped holey g-C3N4 nanosheets have been prepared through a universal self-templating approach with thiocyanuric acid as the single-precursor. By subtly controlling the feeding amount of precursor, the synthesized sulfur-doped holey g-C3N4 nanosheets exhibit excellent visible-light driven photocatalytic hydrogen production activity. The optimized catalyst presents a hydrogen evolution rate of 6225.4 μmol g−1h−1, with an apparent quantum yield of 10 % at 420 nm. Comprehensive characterizations and theoretical calculations suggest that the enhanced photocatalysis is attributed to the synergy of the enlarged surface area, the negatively-shifted conduction band, and the narrowed bandgap due to sulfur-doping and ultra-thin two-dimensional topology. This work highlights the importance of controlling the precursor dosage and inducing sulfur doping into the polymer, providing a promising and reliable strategy to simultaneously regulate the nanostructural and electronic structure of g-C3N4 for highly efficient photocatalysis.

Novel NiFe2O4 deposited S-doped g-C3N4 nanorod: Visible-light-driven heterojunction for photo-Fenton like tetracycline degradation

Fabrication of visible-light-active heterojunction photocatalysts for organic pollutant degradation plays a crucial role in the environmental remediation field. We have fabricated sulfur-doped carbon nitride nanorod (SCNNR) by template free urea assisted hydrothermal method. The facile wet chemical impregnation method was used to deposit nickel ferrite (NFO) nanoparticles on the SCNNR. Various analytical characterization methods were used to study the structural, morphological, optical, and chemical compositions of the prepared photocatalysts. Strong chemical interaction between the NFO and SCNNR nanoparticles enhances the visible-light utilization and also improves the suppression of electron-hole recombination. In particular, the composite 20NFO/SCNNR photocatalyst exhibits greater photo-Fenton-like catalytic degradation of tetracycline (TCN) in the presence of H2O2 under commercial LED light irradiation. The photo-Fenton reaction mechanism and reactive oxygen species for TCN degradation were investigated by the elemental trapping experiment. Moreover, the recycle test proves that the prepared composite photocatalyst is an efficient candidate for environmental remediation applications.

One-pot synthesis of array-like sulfur-doped carbon nitride with covalently crosslinked ultrathin MoS2 cocatalyst for drastically enhanced photocatalytic hydrogen evolution

Constructing noble-metal-free loaded catalyst with high-efficiency photocatalytic activity by a simple and scalable method is of profound significance for fundamental research and practical application. Herein, a simple one-pot method was used to synthesize novel samples of array-like sulfur-doped graphitic carbon nitride (SCN) nanosheets with ultrathin MoS2 loading (MS/SCN-x%). The ultrathin MoS2 cocatalyst was evenly distributed on the surface of SCN and was linked to the main catalyst by covalent chemical bonds. Benefited from the multiple advantages of the array-like porous nanosheets structure with rich exposed surface, covalent cross-linking structure, and enhanced visible light absorption, the MS/SCN-2.5 % composites drastically improve hydrogen evolution performance, which is superior to original MoS2 nanosheet modified by two-step mixing method, and also rivals with Pt/SCN. The designing strategy of photocatalyst modified by noble-metal-free cocatalyst with covalent bond structure provides fascinating insights into enhanced photocatalytic hydrogen evolution.

Enhancing photodegradation activity of g-C3N4 via decorating with S-doped carbon nitride quantum dots by in situ polymerization

In this work, sulfur doped carbon nitride quantum dots (S-CNQDs) were prepared by one-pot copolymerization using melamine and thiourea as starting materials. The composite (g-C3N4/S-CNQDs), showing enlarged surface area, was fabricated by one-step in situ polymerization. The composites displayed much better photocatalytic activity than pristine g-C3N4 in degradation of methyl orange (MO) under UV–visible light irradiation. The removal efficiency of MO reached by 94.3% under visible light (λ ​> ​420 ​nm) illumination within 80 ​min, whereas it was nearly 100% under UV–visible light (λ ​> ​350 ​nm) irradiation within 40 ​min. The enhanced photocatalytic activity of composites is attributed to the doping of S-CNQDs, which leads to higher separation of photo-generated electron-holes, extended visible light response and more active sites. Additionally, the potential mechanism of photocatalytic degradation on MO by g-C3N4/S-CNQDs was proposed. This work presented a simple way for constructing S-CNQDs-based g-C3N4 catalyst.

Surface defect-rich ceria quantum dots anchored on sulfur-doped carbon nitride nanotubes with enhanced charge separation for solar hydrogen production

Designing defect-engineered semiconductor heterojunctions can effectively promote the charge carrier separation. Herein, novel ceria (CeO2) quantum dots (QDs) decorated sulfur-doped carbon nitride nanotubes (SCN NTs) were synthesized via a thermal polycondensation coupled in situ deposition-precipitation method without use of template or surfactant. The structure and morphology studies indicate that ultrafine CeO2 QDs are well distributed inside and outside of SCN NTs offering highly dispersed active sites and a large contact interface between two components. This leads to the promoted formation of rich Ce3+ ion and oxygen vacancies as confirmed by XPS. The photocatalytic performance can be facilely modulated by the content of CeO2 QDs introduced in SCN matrix while bare CeO2 does not show activity of hydrogen production. The optimal catalyst with 10% of CeO2 loading yields a hydrogen evolution rate of 2923.8 μmol h−1 g−1 under visible light, remarkably higher than that of bare SCN and their physical mixtures. Further studies reveal that the abundant surface defects and the created 0D/1D junctions play a critical role in improving the separation and transfer of charge carriers, leading to superior solar hydrogen production and good stability.

Post-Synthetic Derivatization of Graphitic Carbon Nitride with Methanesulfonyl Chloride: Synthesis, Characterization and Photocatalysis.

Bulk graphitic carbon nitride (CN) was synthetized by heating of melamine at 550 °C, and the exfoliated CN (ExCN) was prepared by heating of CN at 500 °C. Sulfur-doped CN was synthesized by heating of thiourea (S-CN) and by a novel procedure based on the post-synthetic derivatization of CN with methanesulfonyl (CH3SO2−) chloride (Mes-CN and Mes-ExCN). The obtained nanomaterials were investigated by common characterization methods and their photocatalytic activity was tested by means of the decomposition of acetic orange 7 (AO7) under ultraviolet A (UVA) irradiation. The content of sulfur in the modified CN decreased in the sequence of Mes-ExCN > Mes-CN > S-CN. The absorption of light decreased in the opposite manner, but no influence on the band gap energies was observed. The methanesulfonyl (mesyl) groups connected to primary and secondary amine groups were confirmed by high resolution mass spectrometry (HRMS). The photocatalytic activity decreased in the sequence of Mes-ExCN > ExCN > CN ≈ Mes-CN > S-CN. The highest activity of Mes-ExCN and ExCN was explained by the highest amounts of adsorbed Acetic Orange 7 (AO7). In addition, in the case of Mes-ExCN, chloride ions incorporated in the CN lattice enhanced the photocatalytic activity as well.

A novel anodic electrochemiluminescence behavior of sulfur-doped carbon nitride nanosheets in the presence of nitrogen-doped carbon dots and its application for detecting folic acid.

The application of carbon dots as a coreactant for Ru(bpy)32+ (where bpy is 2,2'-bipyridine) electrochemiluminescence (ECL) has been widely studied. However, the high cost of Ru(bpy)32+ and its derivatives has prohibited its widespread use in ECL biosensors. Herein, a novel anodic ECL system based on sulfur-doped graphitic carbon nitride nanosheets (S-g-C3N4 NSs) and nitrogen-doped carbon dots (N-CDs) is presented. In this ECL system, N-CDs serve as a new ECL coreactant that can significantly enhance the anodic ECL signal of S-g-C3N4 NSs (approximately 83 times) under optimal conditions. The possible ECL response mechanism of the S-g-C3N4 NSs/N-CDs system is proposed in detail on the basis of cyclic voltammograms, ECL-time curves, and ECL spectra. Furthermore, the ECL signal of the S-g-C3N4 NSs/N-CDs system was quenched by folic acid (FA), which was chosen as a model analyte to study the potential application of the new ECL system. The ECL intensity decreased linearly with the concentration of FA in the range from 0.05 to 200 μM. The detection limit for FA measurement is 16 nM (signal-to-noise ratio of 3). The proposed new ECL system has many advantages over traditional approaches, such as low toxicity and excellent biocompatibility. Especially, the proposed approach can detect FA in diluted human serum samples with satisfactory recoveries, indicating promising application for bioanalysis. Graphical abstract.

Well-dispersed CoSx nanoparticles modified tubular sulfur doped carbon nitride for enhanced photocatalytic H2 production activity

Appropriate dispersion of cocatalyst on semiconductor for improving photocatalytic H2 production efficiency is a challenging work in semiconductor photocatalysis. Herein, we constructed the noble-metal-free CoSx modified tubular sulfur doped carbon nitride (SCN) photocatalysts by chemical precipitation process. The amorphous CoSx well dispersed on SCN served as H2 production sites, which reduced the overpotential and inhibited the recombination of photogenerated carriers by interfacial charge transfer. Maximized H2 production rate of 573.06 μmol g−1 h−1 under visible light irradiation was obtained by optimizing the CoSx loading proportion to 2.4%, which was higher than that of 0.75 wt% Pt/SCN. In addition, a possible mechanism for improved H2 production activity was proposed based on the experiments and discussion. This work provides a new strategy to design rational structure of non-noble metal cocatalyst modified photocatalyst to further improve H2 production performance.

Praseodymium Vanadate-Decorated Sulfur-Doped Carbon Nitride Hybrid Nanocomposite: The Role of a Synergistic Electrocatalyst for the Detection of Metronidazole

The construction of efficient and superior nanostructured materials for the precise determination of contaminants that are hazardous to the environment has gained significant attention by the scientific community. In this regard, we fabricated a nanocomposite consisting of praseodymium vanadate (PrVO4; PrV) anchored to sulfur-doped carbon nitride (PrV/SCN) and applied it to the electrochemical detection of the antibiotic drug metronidazole (MTZ). The structural and crystalline features of the as-prepared PrV/SCN nanocomposite were characterized by various analytical and spectroscopic methods. More distinctly, the PrV/SCN nanocomposite-modified glassy carbon electrode (GCE) exhibits an outstanding linear range (0.001-2444 μM), high sensitivity (1.386 μA/μM cm2), low detection limit (0.8 nM), good reproducibility, and strong anti-interference ability. Notably, the PrV/SCN sensor can determine MTZ in spiked urine and water samples with high recoveries, suggesting its feasibility for real-time applications. Our findings establish PrV/SCN as a robust and promising platform for electrochemical detection. This promotes innovative design for the synthesis of novel functional nanocomposites.

In situ sulfur-doped graphitic carbon nitride nanosheets with enhanced electrogenerated chemiluminescence used for sensitive and selective sensing of l-cysteine.

In this study, in situ sulfur-doped carbon nitride nanosheets (S-g-C3N4 NSs) are used as the signal readout for the sensitive and selective sensing of l-cysteine (l-Cys) in human serum samples based on the competitive coordination chemistry of Cu2+ between l-Cys and S-g-C3N4 NSs. S-g-C3N4 NSs are prepared by using trithiocyanuric acid as a precursor for the first time, which exhibits stronger electrogenerated chemiluminescence (ECL) intensity compared with pristine graphitic carbon nitride nanosheets (g-C3N4 NSs). The ECL signals of the S-g-C3N4 NSs can be quenched by Cu2+ and the subsequent presence of l-Cys can recover the ECL signals of the S-g-C3N4 NSs. These changes are ascribed to the higher coordination ability between Cu2+ and l-Cys than that between Cu2+ and the S-g-C3N4 NSs. On the basis of this, the concentration of l-Cys can be quantitatively determined. Under optimized conditions, the ECL intensity recovery shows a linear relationship with the l-Cys concentration range from 30 nM to 0.2 mM with a lower detection limit of 5 nM (S/N = 3). The proposed method is highly sensitive and selective and is thus particularly useful for fast and simple clinical diagnosis of diseases, such as Alzheimer's disease and cardiovascular disease.

Sulfur doped carbon nitride quantum dots with efficient fluorescent property and their application for bioimaging

Heteroatom doping can drastically alter electronic characteristics of carbon nitride quantum dots, thus resulting in unusual properties and related applications. Herein, we used sulfur as the doping element and investigated the influence of doping on the electronic distribution of carbon nitride and the corresponding fluorescent property. A simple synthetic strategy was applied to prepare sulfur-doped carbon nitride (S-g-C3N4) quantum dots through ultrasonic treatment of bulk S-g-C3N4. Characterization results demonstrated that the prepared S-g-C3N4 quantum dots with an average size of 2.0 nm were successfully prepared. Fluorescent properties indicated that S-g-C3N4 quantum dots have an emission peak at 460 nm and cover the emission spectra region up to 550 nm. Furthermore, the fluorescent intensity is greatly increased due to the sonication of bulk S-g-C3N4 into quantum dots. As a result, S-g-C3N4 quantum dots not only show a blue cell imaging, but have a bright green color. Therefore, S-g-C3N4 quantum dot is a promising candidate for bioimaging benefiting from the efficient fluorescent property, good biocompatibility, and low toxicity.

Highly crystalline sulfur-doped carbon nitride as photocatalyst for efficient visible-light hydrogen generation

Heteroatom-doping is an efficient approach to extend optical absorption beyond 460 nm, which, however, often reduces crystallinity to cause a concomitant detrimental effect on photocatalytic activity. In the present study, we developed a facile approach to synthesize S-doped g-C3N4 with a high crystallinity by self-assembling melamine and tri-thiocyanuric acid, followed by calcination. The resultant optimal S-doped carbon nitride (MTCN-6) exhibited a super-high H2-generation rate of 1511.2 μmol g−1 h-1 (about 11 times higher than that of the pristine CN) under visible light excitation (λ > 420 nm) and an excellent AQE of 3.9% at 420 nm.

Prussian Blue analogue supported on sulfur-doped carbon nitride as an enhanced heterogeneous catalyst for activating peroxymonosulfate

While Prussian Blue (PB) analogues are attractive catalysts for activating peroxymonosulfate (PMS), PB analogues are very small and thus difficult for recovery. Immobilizing PB particles onto graphene is a useful technique which facilitates recovery and also enhances catalytic activities. As doping graphene with sulfur/nitrogen (S/N) increases its electro-conductivity and active sites, the composite of PB and S/N-doped graphene should enhance PMS activation. Thus, this study aims to fabricate such a composite. Unlike conventional S/N-doped graphene prepared via post-modifications, trithiocyanuric acid is used as a precursor, which is converted to S-doped graphitic carbon nitride (SCN). The composite of PB and SCN (PBSCN) is then fabricated by growing a cobalt-based PB analogue on SCN. The resulting PBSCN preserves the crystalline structures, textural properties and catalytic sites of PB and SCN. As degradation of Acid Red 27 (AR) is used as a model reaction, PBSCN exhibits a higher catalytic activity than PB and SCN individually, as well as Co3O4 to activate PMS for AR degradation possibly because SCN may facilitate electron transfer and enhance catalytic activities of PB. PBSCN also remains effective and re-usable over several cycles for AR degradation. These features indicate that PBSCN is a promising catalyst for activating PMS and the fabrication technique demonstrated here can be employed to prepare composites of various PB analogues and carbon nitride to exhibit enhanced catalytic activities.

Sulfur-doped carbon nitride as a non-metal heterogeneous catalyst for sulfate radical-based advanced oxidation processes in the absence of light irradiation

As graphene-like materials are demonstrated as non-metal catalysts to activate persulfate (PSF)/peroxymonosulfate (PMS), co-doping sulfur and nitrogen with graphene is a promising approach to improve catalytic activities. In this study, a convenient one-step approach is adopted to prepare sulfur-doped graphitic carbon nitride (SCN), which shows crumpled morphology and porosity on its surface, making SCN exhibit a much higher surface area than the common CN. Chemical analyses also confirm that a part of N atoms in CN skeleton are substituted by S. To evaluate PSF/PMS activation by SCN, decolorization of Rhodamine B (RhB) is selected as a model test. SCN showed a much higher catalytic activity than carbon nitride (CN) to activate PSF/PMS for RhB decolorization. Behaviors of PSF/PMS activation by SCN are explored by evaluating various effects on RhB decolorization, including temperature, pH, and salt. SCN-activated PSF/PMS for RhB decolorization is much favorable at elevated temperatures and neutral conditions. The presence of NaCl does not significantly inhibit the PSF/PMS activation by SCN. Several radical inhibitors on SCN-activated PMS are also evaluated and the RhB mechanism is shown to involve both sulfate and hydroxyl radicals. Potential mechanisms of PSF/PMS activation by SCN are proposed and ascribed to the more active carbon sites of SCN induced by the co-dopants of sulfur and nitrogen. SCN can be also re-used to activate PSF/PMS without catalytic activity loss. These features demonstrate that SCN is a conveniently-prepared but effective and sustainable non-metal heterogeneous catalyst for activating PSF/PMS.

In situ synthesis of sulfur doped carbon nitride with enhanced photocatalytic performance using DBD plasma treatment under H2S atmosphere

Dielectric barrier discharge (DBD) plasma is considered to be a promising method to synthesize and modify solid catalyst. In this work, DBD plasma was used to synthesize S-doped g-C3N4 catalyst in situ under H2S atmosphere for the first time. XRD, N2 adsorption, UV-Vis, SEM, XPS, EIS, and PL were used to characterize the obtained catalysts. The photocatalytic RhB degradation of as-prepared catalyst was investigated. The results show that, compared with traditional roasting method, H2S plasma treatment can dope more sulfur into g-C3N4 lattice. Such high sulfur content has a significant impact on the morphology, optical property, and electronic structure of the catalyst. The sulfur doped g-C3N4 prepared by plasma treatment displays much higher RhB degradation rate than that prepared by traditional roasting method. This work provides a new strategy for synthesizing heteroatoms doped g-C3N4 based catalyst.

Petal-like CdS nanostructures coated with exfoliated sulfur-doped carbon nitride via chemically activated chain termination for enhanced visible-light–driven photocatalytic water purification and H2 generation

Novel composite photocatalysts consisting of petal-like cadmium sulphide (CdS) nanoparticles and varying amounts of exfoliated sulfur-doped carbon nitride (SCN) were successfully prepared. The as-obtained materials were characterized by field emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflection spectroscopy, photoluminescence spectroscopy and photocurrent-time measurement. Results indicate a strong electric coupling interaction between SCN and CdS due to the heterojunction formed at the amine functionalities sites and oxidized chain terminations of SCN. Two typical pollutants like rhodamine B (RhB) and colorless bisphenol A (BPA) were used for the evaluation of photocatalytic activity. The best-performing CdS/SCN composite (i.e., CS5) synthesized exhibited enhanced visible-light-driven photocatalytic RhB efficiency of about 8.71 and 4.06 times higher than those of pure exfoliated SCN and CdS, respectively. As for BPA degradation, the CS5 composite was 9.00 and 3.61 times more efficient than that of exfoliated SCN and CdS, respectively. These excellent performances were found to be attributable to the remarkable charge carrier separation between CdS and exfoliated SCN with the aid of heterojunction interfacial structures. More importantly, the exfoliated SCN substantially reinforced the photostability of the CdS nanoparticles. Evaluation of the photocatalytic H2 evolution showed that the visible-light H2 production rate of the best-performing CS5 composite was also much greater than the constituents at 247.72 μmol h−1 g−1. Cyclic tests demonstrated the stability of the CS5 composite over repeated use. A possible mechanism was proposed to explain the photocatalytic reaction process. This study provides new insights into the preparation of highly efficient and stable sulfide-based composite photocatalysts, which are promising for implementation in wide-ranging environmental applications.

In-situ synthesis of sulfur doped carbon nitride microsphere for outstanding visible light photocatalytic Cr(VI) reduction

Abstract Sulfur doped graphitic carbon nitride microspheres were synthesized from in situ solvothermal condensation process using trithiocyanuric acid as sulfur source. The photocatalytic activity for Cr(VI) reduction and mechanism on sulfur doped carbon nitride microspheres were investigated in detail. Structure characterizations reveal that the as-prepared sample has incomplete heptazine heterocyclic ring structure. The sulfur species doped into the lattice of carbon nitride was identified as formation of C S and N S in the hybrid framework. Improved conjugated structure, expanding visible light harvesting and elevated conduction band reduction potential were realized by sulfur doping. The photocatalytic activities of the sulfur-doped carbon nitride were evaluated by Cr(VI) reduction under visible light in neutral aqueous solution. After sulfur doping, the catalysts showed much enhanced Cr(VI) reduction rate, about 24 times higher than un-doped sample. This work provides a new strategy for the preparation of sulfur doped polymer semiconductor from mild solvothermal route for the promising application in toxic heavy metal removal in neutral condition.