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XPS high-resolution S2p spectra of (A) Li 2 S, (B) Na 2 S, (C) Na 2 S 4 , (D) K 2 S n and XAES high-resolution SKLL spectra of (E) Li 2 S, (F) Na 2 S, (G) Na 2 S 4 , (H) K 2 S n .
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The identification of surface sulfide and polysulfide species based on the curve fitting of S2p photoelectron spectra and, for the first time, of X-ray excited S KLL Auger spectra has been performed. The different sulfur chemical states present on the surface (sulfide S2-, central S and terminal S in polysulfide chains) could be unambiguously assig...
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... spectra of all the commercial samples ( Fig. 2A-D) showed the presence of multicomponent peaks, consisting of multiple doublets S2p 3/2 -S2p 1/2 (binding energy difference constrained to 1.2 eV together with the intensity ratio 2 : ...
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... SKLL peaks are shown in Fig. 2E-H. Curve tting procedure started from the information obtained on alkali metal sulfate, published in a previous paper. 22 According to it, SKL 23 Polysuldes are chains with variable length of sulfur atoms. One can distinguish sulfur atoms in the center of the chain (central-S) and sulfur atoms at the end of the chain ...
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... 2 S. S2p signal of commercial lithium sulde ( Fig. 2A) showed the presence of ve doublets, whose binding energy values and full-width at half-maximum are listed in Table 2 together with the binding energy of Li1s. The binding energy values ranged between 160.8 eV and 169.6 ...
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... different components were also used to t the SKLL signal (Fig. 2E). The kinetic energy values of the most intense Table ...
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... 2 S. S2p spectra of Na 2 S showed the presence of three doublets (Table 2) ranging from 161.7 eV to 168.8 eV (Fig. 2B). Three doublets were thus used for curve tting the SKLL signal ( Fig. 2F) and the kinetic energy of the 1 D peak of each compo- nent is provided in Table ...
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... 2 S. S2p spectra of Na 2 S showed the presence of three doublets (Table 2) ranging from 161.7 eV to 168.8 eV (Fig. 2B). Three doublets were thus used for curve tting the SKLL signal ( Fig. 2F) and the kinetic energy of the 1 D peak of each compo- nent is provided in Table ...
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... 2 S 4 . In Fig. 2C the S2p signal of Na 2 S 4 sample is shown. The binding energy of the S2p 3/2 component of each doublet is given in Table 2, together with the binding energy of the cation. Polysulde (terminal S) 161.8 ...
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... journal is © The Royal Society of Chemistry 2015 The binding energy values ranged between 161.8 and 168.8 and there are not signicant differences compared to Na 2 S. In Fig. 2G and Table 3 the SKLL signal is shown and the kinetic energy of the 1 D components are listed. K 2 S n . Potassium polysulde showed a multicomponent S2p signal (Fig. 2D). The binding energy values ranged from 161.9 to 168.6 eV ( Table 2). The kinetic energy of the SKLL (Fig. 2H), ranging from 2106.4 eV to 2115.1 eV is listed in Table ...
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... journal is © The Royal Society of Chemistry 2015 The binding energy values ranged between 161.8 and 168.8 and there are not signicant differences compared to Na 2 S. In Fig. 2G and Table 3 the SKLL signal is shown and the kinetic energy of the 1 D components are listed. K 2 S n . Potassium polysulde showed a multicomponent S2p signal (Fig. 2D). The binding energy values ranged from 161.9 to 168.6 eV ( Table 2). The kinetic energy of the SKLL (Fig. 2H), ranging from 2106.4 eV to 2115.1 eV is listed in Table ...
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... 168.8 and there are not signicant differences compared to Na 2 S. In Fig. 2G and Table 3 the SKLL signal is shown and the kinetic energy of the 1 D components are listed. K 2 S n . Potassium polysulde showed a multicomponent S2p signal (Fig. 2D). The binding energy values ranged from 161.9 to 168.6 eV ( Table 2). The kinetic energy of the SKLL (Fig. 2H), ranging from 2106.4 eV to 2115.1 eV is listed in Table ...
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... ion was detected as well. It is worth noting that no signicant modications are induced at the surface of Na 2 S as a consequence of grinding. The comparison of S2p signals recorded on the as received Na 2 S pressed powder and on the powder pressed aer 20 minutes grinding, did not show any signicant change in peak shapes and positions (S.I. Fig. 2 †). Table 2 shows that the binding energy values of S2p compo- nents due to poly-suldes (terminal S À atoms) decrease from 162.8 for Li 2 S to 161.9 eV for K 2 S eV. The binding energy shi, DBE, is due to both intra-atomic effect and extra-atomic effect since, according to the charge potential model 29 it can be written as ...
Citations
... The XPS results of S 2p on the cathode electrodes after the first discharge are illustrated in ) and sulfite (SO 3 2− ) were observed at 169.5 eV and 167.4 eV, respectively. 33,34 When the LCV was lowered to 1.9 V, the relative content of Li 2 S decreased but the ratio of SO 4 2− and SO 3 2− increased. The comparison of XRD results shown in Fig. 2 indicated a clear increase in the amount of Li 2 S in the bulk electrode, evident at 1.9 V. Therefore, from this range onward, the generation of Li 2 S appears to be predominantly governed by reactions within the internal pores; however, on the surface, reactions involving LiTFSI in the formation of the cathode electrolyte interphase (CEI) layers appear to be dominant. ...
The lithium–sulfur (Li–S) battery emerges as a candidate for next-generation batteries owing to its superior energy density and cost-effectiveness. Despite these advantages, the longevity of Li–S batteries remains a complex challenge. The shuttle effect has been identified as a principal factor contributing to degradation, prompting extensive research aimed at mitigating its impact. Recent studies, however, have unveiled that the presence of Li2S exerts a significant influence on the kinetics and stability of the electrochemical reaction. Although lower cutoff voltage directly controls the formation of Li2S, its relationship between lower cut-off voltage and Li2S formation has not been investigated so far. In this study, we regulated the discharge voltage and revealed the relationship between lower cutoff voltage and electrochemical stability. A low lower cut-off voltage increased Li2S formation and the first discharge capacity but reduced Li2S transformation to sulfur, as confirmed by the high overpotential and low charge capacity. Furthermore, repeated cycles at a high discharge exhibited severe capacity loss and deteriorated Coulombic efficiency. By contrast, a high lower cut-off voltage cell exhibited enhanced capacity retention with a low overpotential owing to the inhibition of Li2S formation. Thus, this study provides insights into controlling Li2S formation, which is critical to stabilizing the electrochemical reaction and enhancing the cycle stability of Li–S batteries.
... The N 1s spectrum of the COF did not define amino − NH x groups and mostly N 2 C, which could be attributed to the triazine units of the TFPC precursor of the COF. Finally, pertaining to the analysis of the S 2p region, a major contribution of thioether C-S-C was registered, with binding energies of 163.7 eV (2 p3/2 ) and 164.9 eV (2 p1/2 ) [69,[74][75][76][77]. A minor contribution of sulfate was also registered, binding energies of 169.0 eV (2 p3/2 ) and 170.0 eV (2 p1/2 ) [78]. ...
A sulfur-based COF has been combined with graphitic carbon nitride (CN) in microwave-assisted synthesis to build a COF-CN heterostructure with enhanced photocatalytic activity. The prepared COF-CN were fully characterized, analyzing the textural (N2 isotherms), structural (XRD and FTIR), chemical (elemental analysis and XPS), morphological (HR-STEM), optical (DRS-UV–Vis and photoluminescence) and electrochemical properties (EIS impedance, transient photocurrent, and flat band potential). Different COF-to-CN ratios (5–25 % of COF, wt.) were explored, defining a proportion (20 %) that led to optimum activity for the photocatalytic oxidation of organic contaminants of emerging concern (CECs) due to an enhanced separation of the photogenerated charges and lower bandgap value, 2.55 vs. 2.35 eV. The performance of the optimum COF-CN was further tested for other CECs, demonstrating its benefits in comparison to the bare CN. The materials displayed acceptable reusability and stability. The mechanism of activation highlights the importance played by superoxide radicals and photogenerated holes.
... However, after magnetic separation, the content of Fe 2 O 3 drastically decreases from 8.88 % in the raw coal ash to 0.74 % in the char ash, while the ash content also decreases due to the effective removal of pyrite and its associated minerals in the coal. Fig. 12(a) and (b) present the S2p spectra obtained from the analysis of raw coal and desulfurized char using XPS techniques [19,34,35]. The composition of organic sulfur is estimated through curve-fitting analysis, and the results are shown in Fig. 12(c). ...
Efficient pyrolytic desulfurization with high char yield is a promising yet challenging approach for the cleaner utilization of abundant high-sulfur coal reserves. In this study, we have discovered that a single pyrolysis process under either oxidizing or reducing conditions cannot efficiently remove various sulfur forms while preserving a high char yield. To address this challenge, we propose a three-stage desulfurization process: a low-temperature oxidative pyrolysis (LTOP), a high-temperature reductive pyrolysis (HTRP), and a dry magnetic separation process. LTOP operates in a fluidized bed for only a few minutes to oxidize the diamagnetic pyrite particle surface to Fe2O3 while minimizing char losses. HTRP occurs in another fluidized bed for an appropriate duration to substantially remove organic sulfur while reducing Fe2O3 to highly magnetic Fe3O4 or Fe. Partially magnetized pyrite particles are then removed from the char through magnetic separation. When applied to anthracite coal with a total sulfur content of 4.99%, this process achieves nearly 100% desulfurization for pyritic sulfur and 74.81% for organic sulfur. Ultimately, it recovers 94.5% of the original coal excluding volatiles as char, with 91.6% being low-sulfur char.
... The presence of sulfoxide suggests the doping of the S atom in the heptazine unit by the replacement of N. As this exchange is not isoelectronic, the oxidation of C-S-C moieties to a sulfoxide C-S(═O)-C is expected [55], keeping the aromaticity of the ring. No peaks at ca. 164 eV of thiol -SH groups [66] or sulfide C-S-C at ca. 161 eV [71] were observed. A quantification analysis in SCN-7 led to a 7.03 % (wt.) of S. Fig. 5 illustrates some of the selected STEM micrographs obtained from some selected samples. ...
This work reports the modification of graphitic carbon nitride (CN) through sulfonation (SCN) as an enhanced strategy for photocatalytic activity during the oxidation of benzyl alcohol to benzaldehyde. CN was prepared from melamine and functionalized with -SO3H groups using different doses of chlorosulfonic acid. The textural, structural, morphological, chemical, and optical properties of the prepared samples were characterized by diverse techniques. The increase in the doping dose produced, a decrease in surface area, a blue-shifted absorption edge under irradiation, and a decrease in the recombination charges. The -SO3H improved the kinetics of benzyl alcohol oxidation (BA) in aqueous solution and raised the selectivity to benzaldehyde (BD). An optimum dosage of precursor led to an SCN sample with the highest removal rate and selectivity. This optimized sample was selected for the study of the reactive oxidant species involved during the photocatalytic process, suggesting that the species with the highest contribution during BA oxidation was the superoxide radical, especially in terms of selectivity for the aldehyde formation. This work examples the modification of carbon nitride to enhance the production of an aldehyde with interest in the industry under a sustainable scheme that involves the transformation of light into chemical energy in water.
... This observation was consistent with the S2pspectrum (Fig. 10B), which showed characteristic peaks at 167.85 eV, associated with SO 4 [41]. Another peak at 162.9 eV, attributed to metal sulfides (CuS, FeS2, ZnS), was also observed, indicating the complexation between metal ions and sulfur groups present in RB5 [42]. The Cu2p, Fe2p, and Zn2p spectra (Fig. 10C-E) exhibited significant shifts after adsorption, further confirming the formation of innersphere complexes between the metal ions as a Lewis acid and sulfur groups in RB5 as a Lewis base. ...
The shortage of clean and safe water resources, due to the growing pollution and the high cost of water treatment techniques, has become a real threat. Herein, CuZnFe2O4@N,S-doped biochar (CZF@N,S-BC), a novel magnetic, cleaner, and completely green-based composite, was fabricated using the aqueous extract of Beta vulgaris (sugar beet) leaves for the efficient removal of reactive black dye 5 (RB5) from industrial wastewater discharge. With the aid of numerous techniques, including Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Spectroscopy (SEM), Vibrating Sample Magnetometer (VSM), and zeta potential analyses, CZF@N,S-BC was well-characterized. The results revealed the successful fabrication of CZF@N,S-BC with good magnetic saturation of 12 emu/g and a highly positively charged surface of 32 mV at pH 2. The removal efficiency of RB5 was reached 96.5% at equilibrium time 60 min, and adsorbent dose of 80 mg. The equilibrium data fitted well with the Freundlich isotherm model, while the adsorption kinetics followed a pseudo-second-order model (PSO), with a maximum adsorption capacity of 276.57 mg/g. The thermodynamics results confirmed the physical interaction between the composite and RB5. Additionally, the composite also demonstrated exceptional reusability, maintaining a removal efficiency of 57.27% even after six consecutive cycles. To evaluate the performance of CZF@N,S-BC composite in a real water matrix, the composite was subjected to remove RB5 from a real wastewater sample obtained from an industrial discharge of a textile dyeing industry. Also, a plausible mechanism of RB5 removal by the composite was intensively discussed using XPS before and after adsorption.
... It may be noted that multiple S 2p peaks are expected for coordinated polysulfido ligands and are dependent on the effective charge on the sulfur atoms. 78,148,149 Examples include the assignment of the three S 2p peaks at 161.9, 162.8, and 163.2 eV (observed for a thin film of (NH 4 ) 2 [Pt(S 5 ) 3 ]·2H 2 O on metallic gold) to the sulfur atoms nearest to the metal centers (sulfide like electronic environment, S 2p at 162.0 eV for Na 2 S 150 ), next-nearest sulfur atoms (electronic environment intermediate between sulfides and elemental sulfur), and the furthest sulfur atoms (elemental sulfur like electronic environment, S 2p at 164.2 eV for S 8 150 ), respectively; 149 assignment of the S 2p peaks at 161.4 and 163.0 eV (observed for layers of sulfur electrochemically deposited on gold) to the sulfur atoms nearest to the gold and to the outermost sulfur atoms, respectively; 149 assignment of the corresponding values (161.8 and 163.2 eV) in the case of layers of sulfur deposited electrochemically on platinum; 149 and the assignment of the S 2p peaks at 161.9 and 163.5 eV to the terminal and the central sulfur atom of the polysulfide chain in K 2 S n , respectively. 148 Considering these assignments of the multiple S 2p peaks in the previous reports, 78,148,149 the S 2p peak at 161.3 eV may be assigned to S1 and S5 (closest to the Co(II) centers), the peak at 162.6 eV may be assigned to S2 and S4 (sulfur atoms next-nearest to the Co(II) centers), and the peak at 163.4 eV may be assigned to S3 (furthest from the Co(II) centers) in the present work. ...
... 78,148,149 Examples include the assignment of the three S 2p peaks at 161.9, 162.8, and 163.2 eV (observed for a thin film of (NH 4 ) 2 [Pt(S 5 ) 3 ]·2H 2 O on metallic gold) to the sulfur atoms nearest to the metal centers (sulfide like electronic environment, S 2p at 162.0 eV for Na 2 S 150 ), next-nearest sulfur atoms (electronic environment intermediate between sulfides and elemental sulfur), and the furthest sulfur atoms (elemental sulfur like electronic environment, S 2p at 164.2 eV for S 8 150 ), respectively; 149 assignment of the S 2p peaks at 161.4 and 163.0 eV (observed for layers of sulfur electrochemically deposited on gold) to the sulfur atoms nearest to the gold and to the outermost sulfur atoms, respectively; 149 assignment of the corresponding values (161.8 and 163.2 eV) in the case of layers of sulfur deposited electrochemically on platinum; 149 and the assignment of the S 2p peaks at 161.9 and 163.5 eV to the terminal and the central sulfur atom of the polysulfide chain in K 2 S n , respectively. 148 Considering these assignments of the multiple S 2p peaks in the previous reports, 78,148,149 the S 2p peak at 161.3 eV may be assigned to S1 and S5 (closest to the Co(II) centers), the peak at 162.6 eV may be assigned to S2 and S4 (sulfur atoms next-nearest to the Co(II) centers), and the peak at 163.4 eV may be assigned to S3 (furthest from the Co(II) centers) in the present work. Generation of the corresponding disulfides, namely, o-OMe−C 6 In contrast to the formation of 8 from the reaction of 2 and 3 with S 8 , treatment of 4−7 with S 8 gave back only the starting complexes (Figures S29−S32) and thus indicated the reluctance of the coordinated chelating thiolates in 4−7 to take place in the redox reaction. ...
A series of six binuclear Co(II)–thiolate complexes, [Co2(BPMP)(S–C6H4-o-X)2]¹⁺ (X = OMe, 2; NH2, 3), [Co2(BPMP)(μ-S–C6H4-o-O)]¹⁺ (4), and [Co2(BPMP)(μ-Y)]¹⁺ (Y = bdt, 5; tdt, 6; mnt, 7), has been synthesized from [Co2(BPMP)(MeOH)2(Cl)2]¹⁺ (1a) and [Co2(BPMP)(Cl)2]¹⁺ (1b), where BPMP1– is the anion of 2,6-bis[[bis(2-pyridylmethyl)amino]methyl]-4-methylphenol. While 2 and 3 could allow the two-electron redox reaction of the two coordinated thiolates with elemental sulfur (S8) to generate [Co2(BPMP)(μ-S5)]¹⁺ (8), the complexes, 4–7, could not undergo a similar reaction. An analogous redox reaction of 2 with elemental selenium ([Se]) produced [{Co2(BPMP)(μ-Se4)}{Co2(BPMP)(μ-Se3)}]²⁺ (9a) and [Co2(BPMP)(μ-Se4)]¹⁺ (9b). Further reaction of these polychalcogenido complexes, 8 and 9a/9b, with PPh3 allowed the isolation of [Co2(BPMP)(μ-S)]¹⁺ (10) and [Co2(BPMP)(μ-Se2)]¹⁺ (11), which, in turn, could be converted back to 8 and 9a upon treatment with S8 and [Se], respectively. Interestingly, while the redox reaction of the polyselenide chains in 9a and 11 with S8 produced 8 and [Se], the treatment of 8 with [Se] gave back only the starting material (8), thus demonstrating the different redox behavior of sulfur and selenium. Furthermore, the reaction of 8 and 9a/9b with activated alkynes and cyanide (CN–) allowed the isolation of the complexes, [Co2(BPMP)(μ-E2C2(CO2R)2)]¹⁺ (E = S: 12a, R = Me; 12b, R = Et; E = Se: 13a, R = Me; 13b, R = Et) and [Co2(BPMP)(μ-SH)(NCS)2] (14), respectively. The present work, thus, provides an interesting synthetic strategy, interconversions, and detailed comparative reactivity of binuclear Co(II)–polychalcogenido complexes.
... In conjunction with the Si 2s peak, samples from different treatments showed the presence of sulfur on the surface in at least two different moieties: sulfate and sulfide. Sulfate was detected on all samples ( Fig. 5 and Supplementary Fig. S3) with peaks at roughly 169 eV (Fantauzzi et al., 2015). However, sulfide was only detected on samples B.eD_1y and StB.eD_1y ( Fig. 5 and Supplementary Fig. S3) with a very small peak around 163.5 eV. ...
... Figure 8b shows the spectrum of photoanodes in the indium region. For samples before exposure, the spectrum in the In 61 . The most significant difference between the spectra in the sulfur region of photoanodes before exposure is the intensity of the lines corresponding to S 2− . ...
In this work, ZnIn2S4 layers were obtained on fluorine doped tin oxide (FTO) glass and TiO2 nanotubes (TiO2NT) using a hydrothermal process as photoanodes for photoelectrochemical (PEC) water splitting. Then, samples were annealed and the effect of the annealing temperature was investigated. Optimization of the deposition process and annealing of ZnIn2S4 layers made it possible to obtain an FTO-based material generating a photocurrent of 1.2 mA cm⁻² at 1.62 V vs. RHE in a neutral medium. In contrast, the highest photocurrent in the neutral electrolyte obtained for the TiO2NT-based photoanode reached 0.5 mA cm⁻² at 1.62 V vs. RHE. In addition, the use of a strongly acidic electrolyte allowed the generated photocurrent by the TiO2NT-based photoanode to increase to 3.02 mA cm⁻² at 0.31 V vs. RHE. Despite a weaker photoresponse in neutral electrolyte than the optimized FTO-based photoanode, the use of TiO2NT as a substrate allowed for a significant increase in the photoanode's operating time. After 2 h of illumination, the photocurrent response of the TiO2NT-based photoanode was 0.21 mA cm⁻², which was 42% of the initial value. In contrast, the FTO-based photoanode after the same time generated a photocurrent of 0.02 mA cm⁻² which was only 1% of the initial value. The results indicated that the use of TiO2 nanotubes as a substrate for ZnIn2S4 deposition increases the photoanode's long-term stability in photoelectrochemical water splitting. The proposed charge transfer mechanism suggested that the heterojunction between ZnIn2S4 and TiO2 played an important role in improving the stability of the material by supporting charge separation.
... The XPS spectral features were assigned based on previous research in our group Portilla et al., 2020;Silva-Quiñones et al., 2018) and by others (Abdel-Samad and Watson, 1998;Ansari et al., 2019;Bastl and Baláz, 1993;Calderon et al., 2013;Carver et al., 1972;Derycke et al., 2013;Duan et al., 2018Duan et al., , 2017Fantauzzi et al., 2015;Herbert et al., 1997;Kartio et al., 1997;Kaspar et al., 2010;Mills and Sullivan, 1983;Moulder et al., 1992;Oku and Hirokawa, 1976;Tiwari et al., 2018;Umezawa and Reilley, 1978;Wan et al., 2014). Table 3 summarizes the main peak assignments that are relevant for this study. ...
... Fe ( -Samad and Watson, 1998;Bastl and Baláz, 1993;Silva-Quiñones et al., 2018) S (elemental) 164.0-164.5 (Kartio et al., 1997;Moulder et al., 1992;Wan et al., 2014) S (disulfides) 162.1-162.6 (Bastl and Baláz, 1993;Larrabure et al., 2021) S (sulfate) 168.5-169.0 (Fantauzzi et al., 2015;) Mn (II) oxide 640.7-641.7 (Carver et al., 1972;Oku and Hirokawa, 1976) Mn (III) oxide 641.8-642.4 (Carver et al., 1972;Umezawa and Reilley, 1978) Mn (II) sulfide 640.4-640.5 (Carver et al., 1972;Tiwari et al., 2018) Ag (metallic) 368.0-368.4 ...
... These results show that the XPS spectra of O1s was 531-533 ev (C-O and C --O). Furthermore, the S2p peak (161-168 eV) suggest that SH conjugation was successfully fabricated via chemical methods [51]. HASH and CSHS hydrogels were further evaluated for swelling ratio, mechanical test, and microstructure because these properties significantly impact cell penetration, proliferation, and function in tissue engineering [52,53]. ...
There is a great deal of potential for in vitro follicle growth to provide an alternative approach to fertility preservation. This strategy reduces the possibility of cancer cells re-exposure after transplantation, and it does not require hormone stimulation. Adopting a three-dimensional (3D) culture method helps preserve the architecture of the follicle and promotes the maturity of oocytes. In order to maintain follicle morphology, enhance the quality of mature oocytes, and facilitate meiotic spindle assembly, the current work aimed to develop the 3D in vitro preantral mouse follicle culture method. Thiolated chitosan-co-thiolated hyaluronic (CSHS) hydrogel was designed to evaluate the effects of biomaterials on ovarian follicle development. Isolated follicles from mouse ovaries were randomly divided into alginate (Alg) as a 3D control, thiolated hyaluronic acid (HASH), and CSHS groups. Single follicle was encapsulated in each hydrogel, and performed for 10 days and subsequently ovulated to retrieve mature oocytes on day 11. CSHS hydrogel promoted follicle survival and oocyte viability with maintained spherical morphology of follicle. Matured oocytes with normal appearance of meiotic spindle and chromosome alignment were higher in the CSHS group compared with those in the Alg and HASH groups. Furthermore, CSHS increased expression level of folliculogenesis genes (TGFβ-1, GDF-9) and endocrine-related genes (LHCGR, and FSHR). With various experimental setups and clinical applications, this platform could be applied as an alternative method to in vitro follicle culture with different experimental designs and clinical applications in the long-term period.
