Synthesis of Highly Effective Vanadium Nitride (VN) Peas as a Counter Electrode Catalyst in Dye-Sensitized Solar Cells

Abstract

Vanadium nitride (VN) peas and cubes were synthesized by regulating the molar ratio of the starting materials (urea/VOCl3) via the urea–metal chloride route. The as-prepared VN compounds were subsequently introduced into dye-sensitized solar cells (DSCs) as counter electrode (CE) catalysts for the regeneration of novel organic thiolate/disulfide (T–/T2) and traditional iodide/triiodide (I–/I3 –) redox couples. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization curve results proved that the catalytic activity of the prepared VN was significantly affected by particle shape and particle size. The VN peas showed the highest catalytic activity, followed by the small VN cubes and large VN cubes. The I–/I3 –-electrolyte-based DSCs yielded a high power conversion efficiency (PCE) of 7.29%. The Pt-free VN CE catalysts are more suitable for the new organic redox couples of T–/T2. The DSCs based on VN peas CE showed a PCE of 5.57%, an enhancement of 40.7% relative to the Pt-CE-based DSCs (3.96%).

Highly crystalline, small sized, monodisperse α-NiS nanocrystal ink as an efficient counter electrode for dye-sensitized solar cells

“…Among them, transition metal nitrides [8][9] , carbides [10][11] and sulfides [12][13][14][15] have been researched as CE materials due to both their preferentially electrocatalytic activity and facile synthesis. In this respect, nickel sulfide [16][17][18][19] is one of the most efficient candidates for their high conductivity and excellent electrocatalytic activity.…”

Preparation of Vanadium Nitride Using a Thermally Processed Precursor with Coating Structure

“…It can be widely used as iron and steel additive [1,2], electrode [3,4], catalyst [5,6], superconductor [7], and coating [8,9]. The frequent application of VN, as an important steel additive, can be ascribed to its beneficial effect on fine grain and precipitation strengthening, which can improve the comprehensive performance of steel and reduce the cost of the smelting process by using nitrogen to reduce the vanadium content of steel [10].…”

“…Hence, the pre-reduction during transformation from V 2 O 5 to a high melting point and low-valent vanadium oxides below the melting point of V 2 O 5 is necessary [13], resulting inevitably in a long reaction period. However, using the low-valent vanadium oxides will increase the production cost due to the higher price compared to V 2 O 5 . In addition to the traditional CRN method, VN was prepared by thermal liquid-solid reaction [14]: Ammonolysis of precursor compounds of metal [7], self-propagating high-temperature synthesis [15], sol-gel method [16], chemical vapor deposition [17], mechanical alloying [18] and other methods [19,20].…”

Ab Initio Molecular Dynamics Simulations of Nitrogen/VN(001) Surface Reactions: Vacancy-Catalyzed N2 Dissociative Chemisorption, N Adatom Migration, and N2 Desorption

“…[21][22][23] In addition, they are known to exhibit high catalytic activities for important reactions including hydrogenolysis, hydrogenation, and methanation. [24][25][26][27] The properties of TM nitrides ultimately depend on their nanostructure [28][29][30][31][32] and stoichiometry. [33][34][35] Growth and surface morphological evolution of titanium nitride (TiN), one of the first hard-coating materials, 36,37 have been extensively studied experimentally.…”