Pt-sputtering-like NiCo2S4 counter electrode for efficient dye-sensitized solar cells

Nanograss-Assembled NiCo2S4 as an Efficient Platinum-Free Counter Electrode for Dye-Sensitized Solar Cell

Dye-sensitized solar cells (DSSCs) are often viewed as the potential future of photovoltaic systems and have garnered significant attention in solar energy research. In this groundbreaking research, we introduced a novel solvothermal method to fabricate a unique "grass-like" pattern on fluorine-doped tin oxide glass (FTO), specifically designed for use as a counter electrode in dye-sensitized solar cell (DSSC) assemblies. Through rigorous structural and morphological evaluations, we ascertained the successful deposition of nickel cobalt sulfide (NCS) on the FTO surface, exhibiting the desired grass-like morphology. Electrocatalytic performance assessment of the developed NCS-1 showed results that intriguingly rivaled those of the acclaimed platinum catalyst, especially during the conversion of I3 to I- as observed through cyclic voltammetry. Remarkably, when integrated into a solar cell assembly, both NCS-1 and NCS-2 electrodes exhibited encouraging power conversion efficiencies of 6.60% and 6.29%, respectively. These results become particularly noteworthy when compared to the 7.19% efficiency of a conventional Pt-based electrode under similar testing conditions. Central to the performance of the NCS-1 and NCS-2 electrodes is their unique thin and sharp grass-like morphology. This structure, vividly showcased through scanning electron microscopy, provides a vast surface area and an abundance of catalytic sites, pivotal for the catalytic reactions involving the electrolytes in DSSCs. In summation, given their innovative synthesis approach, affordability, and remarkable electrocatalytic attributes, the newly developed NCS counter electrodes stand out as potent contenders in future dye-sensitized solar cell applications.

Platinum-free dye-sensitized solar cells by flower-like mixed-phase CoxSy/NixSy/MoxSy composites

Fabricated DSSCs using Co_xS_y/Ni_xS_y/Mo_xS_y composites as counter electrodes showed an enhanced photoconversion efficiency.

Metal Sulphides and Their Carbon Supported Composites as Platinum-Free Counter Electrodes in Dye-Sensitized Solar Cells: A Review

Energy sufficiency is a critical requirement for the economic prosperity of modern countries. Efficient harnessing of solar energy using technologies such as the dye-sensitized solar cell could solve the energy problem which persistently plagues developing countries. Despite having a simple operational procedure and modest power conversion efficiency of 13.8%, the dye-sensitized solar cell consists of an expensive platinum counter electrode which makes commercial success futile. Thus, this review intends to establish the progress researchers have attained in the development of sulphide based counter electrodes as alternatives to platinum, thereby lowering cost of production. Metallic sulphides are good electrocatalysts and cheap, hence, they possess the necessary requirements for effective functional counter electrodes. Furthermore, ternary metallic sulphides are known to exhibit higher efficiencies stemming from the synergistic effect produced by the co-existence of two metal ions in a crystal structure, which is believed to induce greater catalytic capability. Incorporation of metallic sulphides with carbon materials, which are exceptional electrical conductors, could potentially produce more efficient counter electrodes. In that regard, this review seeks to establish the effect recently developed composite counter electrodes comprising metallic sulphides and carbon-based materials have induced on the functionality of the counter electrode (CE).

A non-enzymatic glucose sensor based on a CoNi2Se4/rGO nanocomposite with ultrahigh sensitivity at low working potential

A CoNi₂Se₄–rGO nanocomposite fabricated on Ni foam shows excellent efficiency for non-enzymatic glucose sensing at low applied potential.

A Review on the Advancement of Ternary Alloy Counter Electrodes for Use in Dye-Sensitised Solar Cells

A dye-sensitised solar cell (DSSC) counter electrode (CE) plays a vital role in catalysing the conversion of triiodide ( I 3 − ) to iodide ions ( I − ), thereby ensuring the completion of the repetitive cycle of electricity generation. The platinum CE, despite being the standard counter electrode in DSSCs, has drawbacks of platinum’s rarity and high cost. Platinum is an excellent redox catalyst, and consequently, it is the most sought-after metal for catalytic conversions. The huge demand for platinum in the automotive industry for vehicular catalytic converters, the pharmaceutical industry, and in oil refining, as well as other industries, has driven its price to unprecedented levels. The prohibitive price of platinum has caused newer thin film technologies, such as the DSSC which depends on the platinum CE, to be cost-ineffective, thus meaning they cannot compete with the better-established silicon-based solar cells. These problems have stagnated the development of the DSSC, which in turn has dampened larger commercialisation prospects for this thin film technology. With this in mind, this review paper focuses on recent progress in the research and development of alternative cost-effective materials to replace Pt-based CEs. Ternary alloys are amongst the possible alternatives that have been explored, yielding varied results. Alloys, especially ternary sulphides, selenides, and oxides, are attractive as alternatives as they are cheap and are easily fabricated. Ternary alloys also have a synergistic effect produced by the coexistence of two metal ions in a crystal structure, which is believed to induce greater catalytic capability, thus making them ideal cost-effective materials to replace the Pt CE in DSSCs. This review intends to highlight the performance of ternary alloy counter electrodes through the analysis of charge transfer resistance and power conversion efficiencies. Focus is also given to the restrictions and impediments to the attainment of higher power conversion efficiency in alternative CEs. The advances in fabrication of simple ternary alloys, as well as more advanced hierarchical nanostructured counter electrodes, are discussed here in detail. Results obtained to date indicate that the efficiencies of ternary alloy counter electrodes are still below that of the platinum counter electrode, and hence more research is required to enhance their efficiencies.

Ti Porous Film-Supported NiCo₂S₄ Nanotubes Counter Electrode for Quantum-Dot-Sensitized Solar Cells

In this paper, a novel Ti porous film-supported NiCo₂S₄ nanotube was fabricated by the acid etching and two-step hydrothermal method and then used as a counter electrode in a CdS/CdSe quantum-dot-sensitized solar cell. Measurements of the cyclic voltammetry, Tafel polarization curves, and electrochemical impedance spectroscopy of the symmetric cells revealed that compared with the conventional FTO (fluorine doped tin oxide)/Pt counter electrode, Ti porous film-supported NiCo₂S₄ nanotubes counter electrode exhibited greater electrocatalytic activity toward polysulfide electrolyte and lower charge-transfer resistance at the interface between electrolyte and counter electrode, which remarkably improved the fill factor, short-circuit current density, and power conversion efficiency of the quantum-dot-sensitized solar cell. Under illumination of one sun (100 mW/cm²), the quantum-dot-sensitized solar cell based on Ti porous film-supported NiCo₂S₄ nanotubes counter electrode achieved a power conversion efficiency of 3.14%, which is superior to the cell based on FTO/Pt counter electrode (1.3%).

Chemical synthesis of hierarchical NiCo2S4 nanosheets like nanostructure on flexible foil for a high performance supercapacitor

In this study, hierarchical interconnected nickel cobalt sulfide (NiCo₂S₄) nanosheets were effectively deposited on a flexible stainless steel foil by the chemical bath deposition method (CBD) for high-performance supercapacitor applications. The resulting NiCo₂S₄ sample was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and electrochemical measurements. XRD and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of the ternary NiCo₂S₄ sample with a pure cubic phase. FE-SEM and HR-TEM revealed that the entire foil surface was fully covered with the interconnected nanosheets like surface morphology. The NiCo₂S₄ nanosheets demonstrated impressive electrochemical characteristics with a specific capacitance of 1155 F g⁻¹ at 10 mV s⁻¹ and superior cycling stability (95% capacity after 2000 cycles). These electrochemical characteristics could be attributed to the higher active area and higher conductivity of the sample. The results demonstrated that the interconnected NiCo₂S₄ nanosheets are promising as electrodes for supercapacitor and energy storage applications.

Honeycomb-like NiCo2S4 nanosheets prepared by rapid electrodeposition as a counter electrode for dye-sensitized solar cells

Honeycomb-like nickel cobalt sulfide (NiCo₂S₄) nanosheets were directly deposited on fluorine-doped tin oxide substrate by a rapid voltammetric deposition method. The method was also controllable and feasible for preparing NiCo₂S₄ on flexible Ti foil without any heating processes. Compared with Pt, CoS and NiS, NiCo₂S₄ exhibited low charge-transfer resistances and excellent electrocatalytic activity for [Formula: see text] reduction, acting as a counter electrode for a dye-sensitized solar cell. The NiCo₂S₄-based solar cell showed higher power conversion efficiency (7.44%) than that of Pt-based solar cell (7.09%) under simulated illumination (AM 1.5 G, 100 mW cm^-2). The device based on the flexible NiCo₂S₄/Ti foil achieved a power conversion efficiency of 5.28% under the above illumination conditions. This work can be extended to flexible and wearable technologies due to its facile technique.