We report the facile synthesis of hierarchical spiked cobalt selenide (Co0.85Se) microcrystals grown on nickel foam (NF) via a hydrothermal method followed by selenization. Derived from cobalt hydroxyl fluoride (Co(OH)F) microcrystals, the resulting Co0.85Se structures exhibit a robust architecture with well-defined spikes that offer abundant active sites and promote efficient charge transfer, thereby enhancing their electrocatalytic bifunctional activity toward the oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The Co0.85Se/NF electrode delivers low overpotentials of 357 mV for OER and 236 mV for UOR at 100 mA cm(-2). Furthermore, it exhibits a small Tafel slope (34.3 mV dec(-1)) and excellent durability for 24 h at 100 mA cm(-2) during UOR. This simple and cost-effective strategy highlights the potential of hierarchical spiked Co0.85Se microcrystals as highly efficient electrocatalysts for urea-assisted OER and related sustainable energy conversion applications.

In this study, tungsten trioxide (WO3) thin films were successfully fabricated on indium tin oxide (ITO) substrates via both constant current electrodeposition (CCE) and pulsed current electrodeposition (PCE) techniques. The deposition parameters were optimized to achieve films with uniform morphology, high optical transparency, and excellent electrochromic performance. Structural and morphological analyses revealed that all deposited WO3 films were amorphous, while PCE-derived films exhibited improved surface uniformity and nanostructural features compared with those prepared by CCE. Electrochemical measurements conducted in 1.0 M LiClO4/ propylene carbonate electrolyte demonstrated that the film deposited by PCE with 3000 cycles (P600) exhibited the lowest charge transfer resistance (4.84 Omega), highest optical modulation (Delta T = 88.7% at 750 nm), and superior coloration efficiency (157.0 cm2/C). The P600 film also demonstrated rapid switching dynamics (coloration in 1.6 s and bleaching in 0.5 s) and excellent cycling stability with only 3.1% degradation after 300 cycles. Furthermore, the P600 film was successfully integrated into a WO3 & Vert;TiO2 electrochromic full cell, which exhibited reversible device-level electrochromic behavior, high optical contrast, and practical functionality, including the ability to power a red light-emitting diode. These performance enhancements are attributed to the optimized amorphous nanostructure and balanced electrochemically active surface area, which together facilitate efficient ion transport and light modulation. Overall, this work demonstrates that pulsed-current electrodeposition, particularly at 3000 cycles, is a highly effective strategy for engineering high-performance WO3 electrochromic films suitable for energy-efficient smart window and display applications.

This study presents the synthesis of Co0.85Se microsphere-like structures on nickel foam (NF) substrates for high-performance HSC applications. The Co0.85Se microspheres were synthesized using a two-step hydrothermal process, yielding well-distributed—albeit non-uniform—structures on the NF substrate. The electrochemical performance of the Co0.85Se/NF electrode, evaluated in a three-electrode system, demonstrated remarkable characteristics, including a high specific capacity of 719 C g−¹ at 1 A g⁻¹ and outstanding long-term cycling stability, with 87.1% capacity retention over 10,000 charge-discharge cycles. To assess the practical applicability of the Co0.85Se/NF electrode, a hybrid supercapacitor device was assembled using activated carbon (AC) as the negative electrode and Co0.85Se/NF as the positive electrode. The Co0.85Se/NF//AC HSC device exhibited remarkable electrochemical performance, achieving a high energy density of 66.6 Wh kg⁻¹ at a power density of 849.3 W kg⁻¹. It also maintained excellent cycling stability over 10,000 charge-discharge cycles. These findings highlight the significant potential of Co0.85Se microsphere-like structures as high-performance electrode materials for hybrid supercapacitors, paving the way for developing efficient energy storage technologies.

This paper reports the successful synthesis of a novel core/shell structure featuring cobalt selenide nanowires coated with nickel-cobalt layered double hydroxide (Co0.85Se@NiCo-LDH). Co0.85Se nanowires were encapsulated within NiCo-LDH nanosheets on a nickel foam (NF) substrate using a facile three-step synthesis method. Initially, core cobalt carbonate hydroxide hydrate nanowires (CCHH) were grown on an NF substrate using a hydrothermal approach. The Co0.85Se nanowires were then obtained using a selenization process. Finally, a NiCo-LDH nanosheet shell was deposited via an electrodeposition method. The resulting Co0.85Se@NiCo-LDH material exhibited a remarkable specific capacity of 1314C g- 1 at 1.0 A g- 1 owing to its unique core/shell architecture and composition, demonstrating exceptional rate capability with a performance retention of 61.5 % even at a high current density of 20 A g-1. Moreover, it displayed remarkable cycling stability, retaining 89.2 % of its initial capacity after 10,000 cycles. A hybrid supercapacitor device was constructed using Co0.85Se@NiCoLDH as the positive electrode and activated carbon as the negative electrode. This configuration yielded an impressive energy density of 72.2 Wh kg- 1 and a high-power density of 849.9 W kg-1, while maintaining excellent cycling stability with 88.2 % retention after 10,000 cycles. These findings highlight the potential of core/shell architectures for developing high-performance supercapacitors with improved kinetics and stability.

In this study, we present the electrochemical performance of an asymmetric supercapacitor (ASC) composed of one-dimensional manganese oxide (MnO2) nanorods embedded in porous activated carbon sheets (MnO2/PAC) as the positive electrode (positrode), and renewable porous activated carbon (PAC) as the negative electrode (negatrode). This configuration facilitates a high rate of charge/discharge while maintaining substantial specific capacity. The MnO2/PAC composite was successfully synthesized using a hydrothermal technique, while the PAC material was produced through pyrolysis reaction. The MnO2/PAC composite exhibited a maximum specific capacitance of 208.75F g-1 at 0.5 A/g and demonstrated a cyclic stability of 87.43 % in neutral aqueous electrolytes. This notable electrochemical performance is attributed to the significant contribution of the high pseudo-capacitance offered by dense MnO2 nanorods, in addition to the expansive surface area of the activated carbon sheets with closely packed structures. The ASC constructed as PAC//MnO2/PAC displayed a high energy density of 23.3 Wh kg-1 and a power density of 350.4 W kg-1 at a current density of 0.5 A/g. Furthermore, the device showcased exceptional cycling stability, retaining 90.3 % at a current density of 4 A/g. These results underscore the substantial untapped potential of ASC devices for innovative applications in advanced energy storage.

Cobalt-based binder-free electrode materials, such as Co(CO3)0.5(OH)center dot 0.11H2O nanowires (Co@Urea) and Co (OH)F microcrystals (Co@NH4F), were synthesized on a nickel foam substrate by a traditional hydrothermal method using urea and ammonium fluoride (NH4F) as the complexing reagents. The nanowire structure of the Co@Urea electrode promoted efficient charge transfer and high electrochemical active centers. The Co@Urea electrode exhibited a large specific capacity (693.0 C g-1 at 1 A g-1), better rate performance (50.8 % after 20 A g-1), and exceptional cyclic durability (84.0 % capacity retention after 10,000 cycles) compared to Co@NH4F electrode in a three-electrode configuration. A hybrid supercapacitor device was fabricated with Co@Urea as the cathode and activated charcoal as the anode, exhibiting high specific energy and specific power of 53.8 Wh kg-1 and 799.9 W kg-1, respectively. Furthermore, this hybrid device shows excellent long-term stability with 88.2 % capacity retention after 10,000 cycles at a current density of 40 A g-1. This study proposes developing binderfree cobalt-based compounds for electrochemical energy storage applications.

Microsphere-shaped cobalt selenide (Co0.85Se) structures were efficiently synthesized via a two-step hydrothermal process. Initially, cobalt hydroxide fluoride (Co(OH)F) microcrystals were prepared using a hydrothermal method. Subsequently, Co0.85Se microsphere-like structures were obtained through selenization. Compared to Co(OH)F, the microsphere-like Co0.85Se structure exhibited outstanding catalytic activity for the hydrogen evolution reaction (HER) in a 1.0 M KOH solution. Electrocatalytic experiments demonstrated an exceptional HER performance by the Co0.85Se microspheres, characterized by a low overpotential of 148 mV and a Tafel slope of 55.7 mV dec−1. Furthermore, the Co0.85Se electrocatalyst displayed remarkable long-term stability, maintaining its activity for over 24 h. This remarkable performance is attributed to the excellent electrical conductivity of selenides and the highly electroactive sites present in the Co0.85Se structure compared to Co(OH)F, emphasizing its promise for advanced electrocatalytic applications.

The substantial growth of nonprecious and inexpensive electrocatalysts for the oxygen evolution reaction (OER) is vital for commercial usage. In this work, cobalt nickel selenide (CoNi2Se4, called CNSe) thin film nanosheet heterojunctions with iron oxyhydroxide (FeOOH) thin film nanosheets were grown directly on a nickel foam substrate (Ni-foam) using an electrodeposition method. The electrocatalytic activity of CNSe/ FeOOH bilayer nanosheets was evaluated for OER studies using its CNSe and FeOOH counterparts. The CNSe/ FeOOH bilayer thin film exhibited a low overpotential of 222 mV to deliver a benchmark current density of 10 mA cm-2, which was lower than that of the CNSe (327 mV) and FeOOH (276 mV) electrocatalysts. The bilayer electrocatalyst delivered remarkable long-term electrochemical stability for more than 120 h at a constant current density of 10 mA cm-2. The excellent activity was attributed to the synergic effects of CNSe/FeOOH with high electrochemical active sites and feasible charge transfer ability. This study provides new insights for designing a different class of materials using a simple electrochemical deposition route for high-performance OER kinetics.(c) 2023 Elsevier B.V. All rights reserved.

In this study, we present the electrochemical performance of an asymmetric supercapacitor (ASC) composed of one-dimensional manganese oxide (MnO2) nanorods embedded in porous activated carbon sheets (MnO2/PAC) as the positive electrode (positrode), and renewable porous activated carbon (PAC) as the negative electrode (negatrode). This configuration facilitates a high rate of charge/discharge while maintaining substantial specific capacity. The MnO2/PAC composite was successfully synthesized using a hydrothermal technique, while the PAC material was produced through pyrolysis reaction. The MnO2/PAC composite exhibited a maximum specific capacitance of 208.75 F g−1 at 0.5 A g−1 and demonstrated a cyclic stability of 87.43% in neutral aqueous electrolytes. This notable electrochemical performance is attributed to the significant contribution of the high pseudo-capacitance offered by dense MnO2 nanorods, in addition to the expansive surface area of the activated carbon sheets with closely packed structures. The ASC constructed as PAC//MnO2/PAC displayed a high energy density of 23.3 Wh kg−1 and a power density of 350.4 W kg−1 at a current density of 0.5 A g−1. Furthermore, the device showcased exceptional cycling stability, retaining 90.3% at a current density of 4 A g−1. These results underscore the substantial untapped potential of ASC devices for innovative applications in advanced energy storage.

This paper reports the facile hydrothermal synthesis of Co(OH)F crystallites on a nickel-foam (NF) substrate for the oxygen evolution reaction (OER). Scanning and transmission electron microscopy showed that the assynthesized Co(OH)F crystallites consisted of different rhombohedral, octahedral, and decahedral shapes, 0.3-0.5 mu m in size. The desired Co(OH)F catalyst synthesized in this study delivered a lower overpotential of 273 mV at a current density of 10 mA cm-2, with a smaller Tafel slope of only 45 mV dec- 1, compared to other fluoride-containing catalysts because of their unique structural features, higher double-layer capacitance, and rapid charge transfer. Furthermore, a stable potential was maintained for more than 20 h during the chronopotentiometry test at a constant current density of 10 mA cm-2.

Rational designing of electrode materials is of great interest for improving the performance of battery-type supercapacitors. The bimetallic NiCo2S4 (NCS) and CoNi2S4 (CNS) electrode materials have received much attention for supercapacitors due to their rich electrochemical characteristics. However, the comparative electrochemical performances of NCS and CNS electrodes were never studied for supercapacitor application. In this work, microsphere-like bimetallic NCS and CNS structures were synthesized via a facile one-step hydrothermal method by controlling the molar ratio of Ni and Co precursors. The physico-chemical results confirmed that microsphere-like structures with cubic spinel-type NCS and CNS materials were successfully fabricated by this method. When tested as the supercapacitor electrode materials, both NCS and CNS electrodes exhibited battery-type behavior in a three-electrode configuration with outstanding electrochemical performances such as specific capacity, rate performance and cycle stability. Impressively, the CNS electrode delivered a high specific capacity of 430.1 C g−1 at 1 A g−1, which is higher than 345.9 C g−1 of the NCS electrode. Furthermore, the NCS and CNS electrodes showed a decent cycling stability with 75.70 and 84.70% capacity retention after 10,000 cycles. Benefiting from the electrochemical advantage of CNS microspheres, we fabricated a hybrid supercapacitor (HSC) device based on CNS microspheres (positive electrode) and activated carbon (AC, negative electrode), which is named as CNS//AC. The assembled CNS//AC HSC device showed a large energy density of 41.98 Wh kg−1 at a power density of 800.04 W kg−1 and displayed a remarkable cycling stability with a capacity retention of 91.79% after 15,000 cycles. These excellent electrochemical performances demonstrate that both bimetallic NCS and CNS microspheres may provide potential electrode materials for high performance battery-type supercapacitors.

Cobalt fluoride hydroxide (Co(OH)F) crystallite structures with various cobalt concentrations (20, 40, 60, and 80 mM) were grown on nickel foam (NF) substrate using a traditional hydrothermal method and potentially applied as an electrode material for battery-type supercapacitors. Physicochemical analyses showed that the optimal Co(OH)F–60/NF electrode had orthorhombic crystalline phase and comprised of several rhombohedral, octahedral, and decahedral crystallite structures. The electrochemical double-layer capacitance and impedance spectroscopy analyses confirmed that the Co(OH)F–60/NF sample had high active sites and lower equivalent series resistance, respectively. Owing to the more electroactive sites, the Co(OH)F–60/NF electrode delivered a high specific capacity (389.9 C g−1 at 1 A g−1), and remarkable long-term stability (90.02% capacity retention after 10000 cycles) compared to the other Co(OH)F/NF electrodes assessed. A hybrid supercapacitor device (HSC) was designed using the optimized Co(OH)F–60/NF as a positive electrode and activated carbon (AC) as a negative electrode, which delivered a reasonable specific capacity of 130.0 C g−1 and an outstanding stability (92.74% capacitance retention after 8000 continuous cycles). The Co(OH)F–60/NF//AC HSC device provided a maximum energy density of 28.89 Wh kg−1 at a power density of 800.0 W kg−1.

The fabrication of efficient electrocatalysts for water splitting is vital for production of clean fuels. Herein, cobalt-nickel selenide (CoNi2Se4) nanostructures were fabricated on a Ni foam substrate using a facile potentiostatic method at different deposition solution pH levels. Nanoparticle-, fluffy-, and flake-like CoNi2Se4 nanostructures were deposited by changing the aqueous solution pH to 2.0, 2.5, and 3.0, respectively. The desired flake-like CoNi2Se4 electrode fabricated at pH 3.0 presented the best electrocatalytic performance of all CoNi2Se4 nanostructures in this study and required overpotentials as low as 244 and 184 mV to deliver a current density of 10 mA cm(-2) for the OER and HER in 1.0 M KOH, respectively. Furthermore, the electrodes presented long-term stability over 20 h at current densities of 10 and -10 mA cm(-2). Besides, this bifunctional flake-like CoNi2Se4 electrocatalyst delivered outstanding overall water splitting performance and required an external potential of 1.63 V to deliver a current density of 10 mA cm(-2). (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

In this work, mesoporous ZnCo2O4 electrode material with necklace-type nanowires was synthesized by a simple hydrothermal method using water/ethylene glycol mixed solvent and subsequent calcination treatment. The ZnCo2O4 nanowires were assembled by several tiny building blocks of nanoparticles which led to the growth of necklace-type nanowires. The as-synthesized ZnCo2O4 nanowires had porous structures with a high surface area of 25.33 m2 g−1 and with an average mesopore of 23.13 nm. Due to the higher surface area and mesopores, the as-prepared necklace-type ZnCo2O4 nanowires delivered a high specific capacity of 439.6 C g−1 (1099 F g−1) at a current density of 1 A g−1, decent rate performance (47.31% retention at 20 A g−1), and good cyclic stability (84.82 % capacity retention after 5000 cycles). Moreover, a hybrid supercapacitor was fabricated with ZnCo2O4 nanowires as a positive electrode and activated carbon (AC) as a negative electrode (ZnCo2O4 nanowires//AC), which delivered an energy density of 41.87 Wh kg−1 at a power density of 800 W kg−1. The high electrochemical performance and excellent stability of the necklace-type ZnCo2O4 nanowires relate to their unique architecture, high surface area, mesoporous nature, and the synergistic effect between Zn and Co metals.

A new strategy has been successfully developed for highly efficient copper sulfide/lead sulfide (Cu2S/PbS) counter electrodes (CEs) for quantum-dot-sensitized solar cells (QDSSCs). PbS nanoparticles were grown by successive ionic layer adsorption and reaction (SILAR) technique for various cycles (from 1 to 4) on electrochemically deposited Cu2S nanosheets. All the Cu2S and Cu2S/PbS CEs showed petal-like morphology and nanosized PbS nanoparticles were deposited over the Cu2S nanosheets. All FTO/Cu2S/PbS CEs exhibited superior electrocatalytic activity than FTO/Pt and FTO/Cu2S CEs. In particular, QDSSCs with FTO/Cu2S/PbS CE (3 SILAR cycles) exhibited extremely high short-circuit current density (18.08 mA cm(-2)) and fill factor (53.55%), resulting in a significantly enhanced power conversion efficiency as high as 5.28%. This is because the FTO/Cu2S/PbS CE not only exhibits the cascaded, stepwise energy level configuration, which enhances the fast charge transportation, but also serves as a blocking layer to prevent electrons from returning from the electrolyte to the Cu2S. Furthermore, FTO/Cu2S/PbS exhibited excellent electrochemical stability unlike FTO/Cu2S, owing to the passivation of PbS.

Active materials with distinct structures significantly influence the electrochemical properties of supercapacitors. Herein, hierarchical cadmium-sulfide-concealed nickel sulfide (Ni3S2/CdS) nanostructures have been successfully grown on nickel foam using hydrothermal synthesis followed by successive ionic layer adsorption and reaction deposition. The resulting Ni3S2/CdS electrode exhibited a high specific capacity (545.6C g(-1) at 1 A g(-1)) and outstanding cycling stability (capacity retention of 103% after 5000 charge-discharge cycles at a current density of 5 A g(-1)). This is because of the combined synergistic advantages of Ni3S2 (high specific capacity) and CdS (superior mechanical stability). Furthermore, a hybrid supercapacitor assembled using the Ni3S2/CdS cathode and an activated carbon anode showed a notable specific capacitance of 109 Fg(-1) at 1 A g(-1) and a capacitance retention of 110% after 5000 cycles, signifying excellent long-term cycling life. The hybrid supercapacitor exhibited a significantly high energy density of 34 Wh kg(-1) with the power density of 748.8 W kg(-1) at the current density of 1 A g(-1). The above results suggest that the Ni3S2/CdS bilayer can be a prospective candidate for supercapacitors. (C) 2020 Elsevier B.V. All rights reserved.

We report the fabrication of bimetallic NiCo2Se4 and CoNi2Se4 nanostructures on nickel-foam (Ni-foam) substrates via a potentiostatic-deposition method by adjusting the molar ratio of Ni and Co metals. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses show that burl-like clusters with characteristic fluffy NiCo2Se4 and flake-like CoNi2Se4 hierarchical structures were deposited on the Ni-foam substrates. When used as battery-type electrodes in supercapacitors, both NiCo2Se4 and CoNi2Se4 electrodes exhibited outstanding capacity and good electrochemical properties. The CoNi2Se4 electrode delivered excellent capacity and cycling stability (602 C g(-1) at 1 A g(-1) and 98.30% retention after 5000 cycles at 40 A g(-1)) when compared to the NiCo2Se4 electrode (353 C g(-1) at 1 A g(-1) and 96.83% retention after 5000 cycles at 40 A g(-1)). Furthermore, as-deposited NiCo2Se4 and CoNi2Se4 hierarchical structures were employed as efficient electrocatalysts for water oxidation in alkaline solutions. NiCo2Se4 and CoNi2Se4 electrocatalysts showed low overpotentials of 257 and 244 mV in a 1.0 M KOH aqueous solution, respectively. The electrocatalysts also exhibited prolonged stability (NiCo2Se4 and CoNi2Se4 maintained currents of 95.6% and 97.5%, respectively, over 10 h), which makes them comparable to well-known Ni and Co-based catalysts. Collectively, the as-deposited NiCo2Se4 and CoNi2Se4 are the most efficient bifunctional electrodes and electrocatalysts for application in battery-type supercapacitors and the oxygen evolution reaction, respectively, and can potentially be applied for energy conversion and storage processes. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Bimetallic CoNi2Se4 nanostructures on nickel-foam substrates were fabricated by a potentiostatic deposition method by adjusting the deposition solution pH, and used as electrode materials in battery-type supercapacitors. The electrodeposition solution pH had an important role in the fabrication of the desirable CoNi2Se4 nanostructures. At a deposition solution p(H) of 2.0, the synthesized product contained CoNi2Se4 nanoparticles. In contrast, a partially converted flake-like morphology was obtained at p(H) = 2.5. The appropriate flake-like morphology was formed by increasing the deposition solution pH to 3.0. The robust flake-like structure facilitated the electron transport during redox reactions, providing an excellent electrochemical behavior in terms of specific capacity, rate capability, and cyclic stability. A battery-type supercapacitor based on the flake-like CoNi2Se4 structure exhibited a maximum specific capacity of 632.5 C g(-1) at a current density of 1 A g(-1) and excellent rate performance (capacity retention of 91%) in the range of 1 to 40 A g(-1). The material retained 83.31% of its initial capacity after 3000 cycles of charging/discharging at a current density of 40 A g(-1), which suggests a high long-term cycling stability. The excellent electrochemical performance of the CoNi2Se4 electrode material make it very promising for application in supercapacitors. (C) 2019 Elsevier B.V. All rights reserved.

A novel hierarchical cobalt nickel sulfide (CoNi2S4) nanostructure resembling the rambutan fruit was obtained by a simple one-step hydrothermal method using ethylene glycol as the solvent. Scanning and transmission electron microscopic analyses revealed that the as-synthesized CoNi2S4 consists of numerous hairy nanorods grown radially on top of individual sphere-like core structures. The CoNi2S4 hierarchical material was applied as a potential electrode for supercapacitors in both three- and two-electrode systems. The hairy nanorods and spheres were highly interconnected to form hierarchical rambutan-like CoNi2S4 structure with increased active areas of the electrode, and this facilitate effective charge transport from the nanorods to the spherical core structure. When evaluated as an electrode material in a three-electrode system, CoNi2S4 with the hierarchical structure delivered a high specific capacitance of 1102.22 F g (-1) at a current density of 1A g(-1) with excellent rate capability (68.55% capacitance retention as the current increases from 1 to 10A g(-1)) and significant cycling stability (75% retention after 3000 cycles). The electrochemical properties of the hierarchical CoNi2S4 were also investigated in a symmetrical cell arrangement using 2 M aqueous KOH as the electrolyte. The symmetric aqueous supercapacitor exhibited a specific capacitance of 482 F g(-1) at 1 A g(-1) with maximum energy density of 16.74 Wh kg(-1) and maximum power density of 10.2 kW kg(-1). Furthermore, the symmetric supercapacitor exhibited excellent cycling stability, showing 92.85% capacitance retention even after 5000 cycles. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Molybdenum disulfide (MoS2) films are electrochemically synthesized on F-doped SnO2 (FTO) substrates using potentiostatic electrodeposition (ED) at a constant −1 V for 20–60 min. The MoS2 is deposited according to island growth mode. As the ED time increases to 40 min, the clusters of MoS2 nano particles enlarge and thicken, but maintain nanopores between the clusters. Additional increase in ED time (to 60 min) causes clusters to merge and make the film denser. Furthermore, this MoS2 film exhibits cracks due to stress accumulated in the film. The film FTO/MoS2 (40 min) shows significantly enhanced electrocatalytic activity compared to other films. This is because the FTO/MoS2 (40 min) not only has more electrochemically active sites but also significantly facilitates charge transfer and mass transport. When it is employed as the counter electrode (CE) for quantum-dot and dye-sensitized solar cells (QD-SSC, D-SSC), the QD-SSC with FTO/MoS2 (40 min) CE exhibits even higher overall energy conversion cell efficiency (3.69%) than that with Pt CE (2.16%). Moreover, the D-SSC with FTO/MoS2 (40 min) CE exhibits cell efficiency (7.16%) similar to that with FTO/Pt CE (7.48%). This indicates that MoS2 is a promising CE for all QD-SSCs and D-SSCs.