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Remodelling hierarchical NiCo2O4@ZnS nanorods with multi-walled carbon nanotubes as a counter electrode for dye-sensitized solar cell applications
(2026-12-01)
Nukunudompanich, Methawee
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Nachaithong, Theeranuch
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Phumuen, Phatcharin
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Wannabut, Wassana
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Kunbuala, Neeraphat
A hierarchical NiCo<inf>2</inf>O<inf>4</inf>@ZnS/MWCNT (NCO@Z-MWCNTs) nanocomposite was synthesized to serve as a platinum-free counter electrode for dye-sensitized solar cells (DSSCs). The nanocomposite comprised spinel NiCo<inf>2</inf>O<inf>4</inf> nanorods, ZnS associated with the surface of the nanorods, and an interconnected multi-walled carbon nanotube (MWCNT) network, and it was synthesized via a low-temperature solution-based hydrothermal method. XRD confirmed the presence of cubic NiCo<inf>2</inf>O<inf>4</inf> and zinc blende ZnS phases, while FESEM–EDS and XPS analyses verified the incorporation of ZnS and the formation of a conductive carbon framework interconnecting adjacent nanorods. ZnS, rather than acting as an isolated catalytic component, was considered to contribute additional sulfide-related surface sites and to modulate the interfacial electronic environment of the NiCo<inf>2</inf>O<inf>4</inf> nanorods, which likely facilitated redox reactions involving the I−/I<inf>3</inf>− couple. Meanwhile, the MWCNT network established continuous electron transport pathways, effectively reducing interfacial resistance and enhancing charge-transfer efficiency. Thermogravimetric and electrochemical analyses revealed enhanced thermal stability, improved redox kinetics, and a significant reduction in charge-transfer resistance compared with pristine NiCo<inf>2</inf>O<inf>4</inf>.The optimized NCO@Z–MWCNT 9wt% counter electrode achieved a power conversion efficiency of 10.03% under AM 1.5 G illumination, exceeding that of the Pt reference device (9.6%). Overall, the improved performance was attributed to the combined contributions of ZnS surface modification and the conductive MWCNT network, which together enhanced charge transport and electrocatalytic activity. This work demonstrates a scalable strategy for developing cost-effective, durable, and high-performance counter electrodes for dye-sensitized solar cells.
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New hybrid high performance dye-sensitized solar cells using CoNi2Se4@SiO2 core-shell integrated with graphene quantum dots as counter electrodes
(2026-10-01)
Areerob, Yonrapach
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Nachaithong, Theeranuch
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Phumuen, Phatcharin
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Wannabut, Wassana
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Nijpanich, Supinya
A novel CoNi₂Se₄@SiO₂ core–shell nanostructure decorated with graphene quantum dots (CNS@Si–GQDs) was synthesized via a simple hydrothermal method and investigated as a Pt-free counter electrode for dye-sensitized solar cells (DSSCs). The optimized CNS@Si–GQDs electrode with 7 ppm GQD loading exhibited excellent electrocatalytic activity toward the I₃−/I− redox reaction, delivering a photoelectric conversion efficiency (PCE) of 8.10%, slightly higher than that of the conventional Pt electrode (8.03%). The optimized device also achieved a high short-circuit current density (Jsc) of 18.67 mA cm−2, with a Voc of 0.75 V and a fill factor (FF) of 0.57. Electrochemical impedance spectroscopy revealed that the CNS@Si–GQDs (7 ppm) electrode possessed the lowest charge-transfer resistance (Rct = 241.62 Ω cm2), significantly lower than those of the 3 ppm and 5 ppm electrodes, indicating enhanced interfacial electron-transfer kinetics and catalytic activity. Tafel polarization analysis further confirmed improved exchange current density and faster triiodide reduction kinetics after GQD incorporation. The enhanced electrochemical performance was attributed to the synergistic interaction between the conductive GQD network and the CNS@SiO₂ core–shell structure, which increased the electroactive surface area, promoted electron mobility, and provided abundant catalytic active sites. Additionally, the SiO₂ interfacial layer helped suppress charge recombination and stabilize the hierarchical nanostructure. This study demonstrates a scalable, low-cost, and efficient Pt-free strategy for next-generation DSSCs and provides insights into the design of advanced electrocatalysts for sustainable solar energy conversion.
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Self-activation of carbons derived from bio-waste cabbage for a green supercapacitor based on seawater electrolyte
(2024-12-01)
Phakkhawan, Authit
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Sakulkalavek, Aparporn
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Chanlek, Narong
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Nijpanich, Supinya
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Ngernyen, Yuvarat
Carbonized carbons (CC) derived from cabbage were self-activated via a carbonization process at 500–900 °C in Ar. CC synthesized at 800 °C (CC-800), containing KCl, CaCO<inf>3</inf>, Ca(ClO)<inf>2</inf>, K<inf>2</inf>SO<inf>4</inf>, and Ca<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>(OH), has the highest specific surface area (S<inf>BET</inf>, 130.04 m2 g−1), a high specific capacitance (64.06 F g−1), and an excellent rate capability (65.12 %). After washing the CC-800 powder in either deionized (DI) water (AC-DI) or hydrochloric acid (HCl) followed by DI water (AC-HCl-DI), S<inf>BET</inf> values increased to 919.22 and 1146.51 m2 g−1, respectively. KCl, Ca(ClO)<inf>2</inf>, and K<inf>2</inf>SO<inf>4</inf> are removed from the AC-DI, whereas all compounds are washed from the AC-HCl-DI. Removing these compounds enlarges S<inf>BET</inf> values, specific capacitance (114.47 F g−1 at 0.5 A g−1), and rate capability (68.95 %). A high capacitance retention of 97.56 % after 20,000 cycles was achieved from the AC-HCl-DI electrode with 6 M KOH. 0.6 M NaCl and seawater were applied as green electrolytes with the AC-HCl-DI electrode, resulting in the promising specific capacitance of 116.89 and 102.21 F g−1 at 0.5 A g−1, respectively. Symmetric AC-HCl-DI/seawater/AC-HCl-DI cell gives a high energy density of 2.32 Wh kg−1 at a large power density of 0.25 kW kg−1. The four serial AC-HCl-DI/seawater/AC-HCl-DI coin cells could light an LED over 60 s.
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Customized electrospun multilayer composite polymer electrolytes: PEO-PAN-NbO2 nanofiber membrane for enhancing the performance of lithium-ion batteries
(2024-06-01)
Yonchai, Chutarat
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Kidkhunthod, Pinit
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Siriroj, Sumeth
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Padchasri, Jintara
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Sonsupap, Somchai
Ground-breaking research into the development of a multilayer composite polymer electrolyte aims to enhance the safety associated with liquid electrolytes utilized in lithium batteries. The electrolyte consists of two outer layers made of electrospun poly(vinylidene fluoride) (PVDF) and a middle layer comprised of a fibrous membrane containing PEO, PAN-PEO, PEO-NbO<inf>2</inf>, and PAN-PEO-NbO<inf>2</inf>. The investigated PEO-PAN-NbO<inf>2</inf> system demonstrates a higher room temperature ionic conductivity of 2.451 × 10−1 mS cm−1 than that of single-phase electrolyte systems. Incorporating inorganic fillers such as NbO<inf>2</inf> into PEO polymer electrolytes, in conjunction with PAN copolymerization, significantly enhances ionic conductivity and amplifies surface area. Consequently, the utilization of these techniques that demonstrate increased polymer membranes leads to improved efficiency and security of solid-state electrochemical devices. The multilayer composite polymer electrolyte is created by continuous electrospinning, which allows for precise control and improves safety features.
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A novel of WS2–MoCuO3 supported with graphene quantum dot as counter electrode for dye-sensitized solar cells application
(2023-12-01)
Areerob, Yonrapach
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Oh, Won Chun
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Hamontree, Chaowalit
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Nachaithong, Theeranuch
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Nijpanich, Supinya
A novel tungsten disulfide-molybdenum copper oxide composite supported with graphene quantum dots (WM@GQDs) has been synthesized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs) using a simple and low-cost ultrasonication method. The unique structure of WM@GQDs exhibits excellent power conversion efficiency due to its high catalytic activity and charge transport properties. In addition, the graphene quantum dots (GQDs) provide more active sites in the zero-dimensional materials for an I/I<inf>3</inf>− redox reaction which can improve the electrical and optical properties of the composite. The results indicate that the amount of GQDs in the composite affect the effectiveness of solar devices. When 0.9%wt of GQDs was used, the WM@GQDs composite achieved an efficiency of 10.38%, which is higher than that of the expensive platinum CE under the same conditions. The mechanism behind the improved power conversion efficiency (PCE) of the composite sample is also discussed in detail. Therefore, WM@GQDs can be an efficient material to replace platinum in DSSCs as a CE.
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Synthesis of novel MoWO4 with ZnO nanoflowers on multi-walled carbon nanotubes for counter electrode application in dye-sensitized solar cells
(2022-12-01)
Areerob, Yonrapach
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Hamontree, Chaowalit
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Sricharoen, Phitchan
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Limchoowong, Nunticha
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Nijpanich, Supinya
Novel MoWO<inf>4</inf> with ZnO nanoflowers was synthesized on multi-walled carbon nanotubes (MW-Z@MWCNTs) through a simple hydrothermal method, and this unique structure was applied as a counter electrode (CE) for dye-sensitized solar cells (DSSC) for the first time. The synergetic effect of ZnO nanoflowers and MoWO<inf>4</inf> on MWCNTs was systematically investigated by different techniques. The amount of MWCNTs was optimized to achieve the best DSSC performance. It was found that the 1.5% MW-Z@MWCNTs composite structure had the highest power conversion efficiency of 9.96%, which is greater than that of traditional Pt CE. Therefore, MW-Z@MWCNTs-based CE can be used to replace traditional Pt-based electrodes in the future.

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