Opaque Pt counter electrodes for dye‐sensitized solar cells

Summary The exorbitant cost, corrosive nature and rare abundance of Pt as counter electrodes has hampered the availability of dye‐sensitized solar cells (DSSCs). Perovskites, the complex metal oxides that have a diverse variety of oxidation states and high oxygen vacancy concentrations, have sparked a lot of interest in energy storage and conversion, with researchers focusing on alternative ideas for rate‐cut counter electrodes to magnify the cost‐cutting of DSSCs. Herein, instead of Pt, the three hydrothermally synthesized perovskites LaCeNiO3, LaNiO3, and CeNiO3 are employed as photocathodes for the fabrication of DSSCs. The electrochemical studies reveal that their electrocatalytic activity towards the iodine/iodide electrolyte is akin to a typical Pt photocathode. The electrons released by the perovskites by oxygen reduction reaction on its surface reduce the I3− to I−, thus the regeneration of the dye to its ground state happens by collecting electrons from the I− ion redox mediator, and finally oxidation of I− to I3− takes place. The LaCeNiO3 shows a higher short circuit current (13.75 mA cm−2) with a power conversion efficiency of 3.46%. It has 579 mV of open‐circuit voltage with a 0.37 fill factor value. The LaNiO3 shows lower values in comparison with LaCeNiO3 because the A‐site cation doping creates lattice deficiencies in LaCeNiO3 making it good for the iodine reduction reaction.

FF = \frac{Vmax \times Imax}{Voc \times Isc},

% PCE = \frac{Voc \times Isc \times FF}{italicPin} .

Section: Resultsmentioning

confidence: 99%

Configuration of Ce‐doped LaNiO ₃ as an alternative to platinum‐free counter electrodes for dye‐sensitized solar cells

Gunasekaran

James

Maridevaru

et al. 2022

“…Atli et al specified that an opaque Pt CE can be employed for efficient DSSCs. 22 Natural dye extracted from St. Lucie cherry was utilized for DSSCs. 23 Ni-doped TiO2 nanoparticle showed a PCE of 5.08% for DSSCs with 0.05 M of nickel doping.…”

Section: Introductionmentioning

confidence: 99%

“…In this direction, there are important works reported in recent years. Atli et al specified that an opaque Pt CE can be employed for efficient DSSCs 22 . Natural dye extracted from St. Lucie cherry was utilized for DSSCs 23 .…”

Section: Introductionmentioning

confidence: 99%

Ni‐doped TiO ₂ / TiO ₂ homojunction photoanodes for efficient dye‐sensitized solar cells

Atılgan

Yildiz

2022

Self Cite

The development of novel bilayer photoanodes plays an essential role in dyesensitized solar cell (DSSC) applications to fabricate efficient devices. Herein, a novel homojunction photoanode consisting of undoped and Ni-doped TiO 2 layers with trace amounts of Ni dopant (0.5% at.) was prepared. After a systematic study on photoconversion efficiency that changes with tuning the location of the doped layer, an in-depth understanding was obtained regarding the physical mechanism of the coupling of structural, optical and electrical properties. We demonstrated that the doped layer can be utilized for highperformance DSSCs by employing a homojunction photoanode consisting of an upper-layer of Ni-doped TiO 2 and a lower-layer of undoped TiO 2 to dramatically increase the photoconversion efficiency. We monitored that the light absorption ability of the dye-loaded photoanodes strongly improved with the bilayer (Ni-doped TiO 2 /TiO 2 ), leading to a higher short circuit current. From impedance spectroscopy (Mott-Schottky plots), compared to both undoped and the doped single-layer analogues, a greater shift to more negative flat band potential was noticed for the bilayer and, therefore, a higher open-circuit voltage was achieved. From electrochemical impedance spectroscopy analysis, it was found that chemical capacitance decreases, while recombination resistance increases after Ni incorporation in the photoanode. They were associated with a reduction in the number of immobile electrons trapped by defect states. A relatively longer electron lifetime of 10.18 ms and diffusion length of 63.2 μ m were obtained for the device assembled with the homojunction (Ni-doped TiO 2 /TiO 2 ). The PCE (6.08%) of the device assembled with the bilayer was superior to its single-layer analogue (4.13%), owing to its enhanced light harvesting capability, proper band alignment, improved injection ability, fast electron transport and better collection efficiency. Our results shed light on important characteristics of a homojunction photoanode, which can be considered for future studies and applications.

“…The world's energy consumption has been drastically increasing, and it is believed that the energy needs will multiply more in the forthcoming days. 1 To full-fill the needs of electrical energy consumption, there is an immediate urge to focus on the efficient development and storage of clean, green, and safe energy, especially from ample renewable resources. The notable energy conversion and storage devices available currently are solar cells, fuel cells, water splitting, supercapacitors, and batteries.…”

Section: Introductionmentioning

confidence: 99%

“…The former mode denotes the in-plane optical motion of tungsten (W) and sulfur (S) atoms in opposite directions, whereas the latter is due to out-of-plane optical vibrations of sulfur atoms. There is a frequency difference of $58 cm À1 for WS 2 QDs between A1 g and E 1…”

mentioning

confidence: 99%

Designing of Kirkendall effect assisted CoFe : WS ₂ nanoboxes for dye‐sensitized solar cell and supercapacitor applications

Rasappan

Thangamuthu²,

Velauthapillai

2022

In this study, CoFe: tungsten disulfide (WS 2 ) hollow nanoboxes were synthesized for dye-sensitized solar cell (DSSC) and supercapacitor (SC) applications.Hollow nanoboxes structured as CoFe: WS 2 were synthesized using the facile hydrothermal and co-precipitation methods, combined with the ultrasonication technique as a pioneer. The morphological transformation from nanocubes to hollow nanoboxes (Kirkendall effect) was observed upon the incorporation of WS 2 quantum dots in an optimal ratio. The CoFe: WS 2 -2 hollow nanoboxes were employed as the counter electrode (CE) in DSSCs, which exhibit phenomenal catalytic activity in I 3 À electrolyte reduction and achieved a maximum power conversion efficiency (PCE) of 5.7%. Increased active sites for red-ox reaction and enhanced surface area due to the Kirkendall effect made the power conversion of the CoFe: WS 2 -2 DSSC device superior to that of platinum devices (4.0%). Supercapacitor performance of the CoFe: WS 2 -2 hollow nanoboxes shows a maximum specific capacitance of 551 F/g at a Current density of 1 A/g and the capacitance retention was noticed to be 88.96% in the three-electrode system using 2 M KOH as electrolyte. The asymmetric supercapacitor device exhibits an energy density of 37.18 Wh/kg and a power density of 875 W/kg at a current density of 1 A/g. The constructed CoFe: WS 2 -2//AC device reveals capacitance retention and coulombic efficiency of 71.99% and 98.18% after 6000 cycles, in the SC, respectively. The result emphasizes that hollow nanoboxes structured CoFe: WS 2 -2 can be an outstanding electrode in both DSSCs and SCs devices.