Synergistically Enhanced Electrochemical Performance of Ni₃S₄–PtX (X = Fe, Ni) Heteronanorods as Heterogeneous Catalysts in Dye-Sensitized Solar Cells

Abstract

Platinum (Pt)-based alloys are considerably promising electrocatalysts for the reduction of I/I and Co/Co redox couples in dye-sensitized solar cells (DSSCs). However, it is still challenging to minimize the dosage of Pt to achieve comparable or even higher catalytic efficiency. Here, by taking full advantages of the Mott-Schottky (M-S) effect at the metal-semiconductor interface, we successfully strategize a low-Pt-based M-S catalyst with enhanced electrocatalytic performance and stability for the large-scale application of DSSCs. The optimized M-S electrocatalyst of NiS-PtX (X = Fe, Ni) heteronanorods is constructed by rationally controlling the ratio of Pt to transition metal in the hybrids. It was found that the electrons transferred from NiS to PtX at their interface under the Mott-Schottky effect result in the concentration of electrons onto PtX domains, which subsequently accelerates the regeneration of both I/I and Co/Co redox shuttles in DSSCs. As a result, the DSSC with NiS-PtFe manifests an impressive power conversion efficiency (PCE) of 8.79% and 5.56% for iodine and cobalt-based electrolyte under AM1.5G illumination, respectively. These PCEs are obviously superior over those with NiS-Pt, PtFe, NiS, and pristine Pt electrodes. The strategy reported here is able to be further expanded to fabricate other low-Pt-alloyed M-S catalysts for wider applications in the fields of photocatalysis, water splitting, and heterojunction solar cells.

Structural Engineering on Pt-Free Electrocatalysts for Dye-Sensitized Solar Cells

“…Impressively, the single-crystal CoSe 2 CE produces an η of 10.20% with a V OC of 0.753 V, a J SC of 18.55 mA/cm −2 , and a FF of 0.73, which is better than the Pt CE (8.17%). The Ni 3 S 4 -PtFe heteronanorods are highly monodispersed with an average length of ∼34.0 nm and an average diameter of 9.0 nm, as shown in Figure 8(h) [75]. The DSSCs using Ni 3 S 4 -PtFe produce an η of 8.79%, which is higher than that of the Pt CE (7.83%).…”

“…And CoSe 2 /CoSeO 3 -NP has a larger reaction area than the nanorod and nanocube of CoSe 2 /CoSeO 3 , confirmed by the electrochemical double-layer capacitance, which is positively related to the Figure 8. [78], (c) double-shelled ball-in-ball hollow sphere [70,74], (d) hollow spherical particle [71], (e) acicular nanorod array [49], ( f-h) nanorod [53,54,75], (i and j) nanosheet [55,66], (k and l) nanowall [64,72], and (m) hierarchical nanosphere with nanorod [77]. reaction area.…”

Enhanced electrocatalytic performance of nickel diselenide grown on graphene toward the reduction of triiodide redox couples

“…6, two typical pairs of oxidation-reduction peaks can be clearly seen in each CV curve, indicating the same electrocatalytic mechanism toward triiodide reduction. 12,41 From low potential to high Table 1 The corresponding values of series resistance (R S ), charge-transfer resistance (R ct ), limiting diffusion current density (J lim ), peak-to-peak separation (E pp ) and cathodic peak current density (J Red-1 ) potential, the reactions of four oxidation-reduction peaks can be ascribed to eqns (3)-(6):…”

“…[8][9][10] Nevertheless, its drawbacks of high cost (US$50/gram), low natural abundance in earth (0.0037 ppm), and being easily decomposed to harmful PtI 4 and H 2 PtI 6 byproducts, make it unsuitable in terms of sustainable development. 11,12 Given the above considerations, it is of great importance and desirability to develop a low-cost, earth-abundant and anticorrosive Pt-free electrocatalyst with high electrical conductivity and excellent catalytic activity simultaneously for the reduction of I 3 . [13][14][15][16][17] Given the above considerations, earth-abundant transitional metal dichalcogenides (MX 2 , M ¼ Fe, Co, or Ni and X ¼ S or Se) have been applied as CE electrocatalysts and found to be competitive Pt alternatives, beneting from their intrinsic metallic properties.…”

Low‐Crystalline NiS Hybridized with BiOCl Nanosheet as Highly Efficient Electrocatalyst for Dye‐Sensitized Solar Cells

“…synthesized 3D FeSe 2 microspheres as CE for DSSCs, which gave a slightly higher PCE of 8.39% than that of Pt CE based DSSC (8.20%) . Besides, CoS,, Co 3 S 4 , CoS 2 , Ni 3 S 2 , NiS,, Ni 3 S 4 , NiS 2 , MoS 2 , Cu 2 ZnSnS 4 (CZTS), Cu 2 SnS 3 , FeS and NiSe have also been developed as CE in DSSCs, and proved excellent catalytic performance for I 3 − reduction. Nevertheless, commercial application of the aforementioned materials in DSSCs still faces many challenges.…”