Boron Nitride/Sulfonated Polythiophene Composite Electrocatalyst as the TCO and Pt-Free Counter Electrode for Dye-Sensitized Solar Cells: 21% at Dim Light

Abstract

Boron nitride (BN) is newly introduced as a nonmetal electrocatalyst for the counter electrode of a dye-sensitized solar cell (DSSC). By applying a conductive binder of sulfonated poly(thiophene-3-[2-(2methoxyethoxy)ethoxy]-2,5-diyl) (s-PT), the BN/s-PT composite film was successfully wrapped around each carbon fiber (CF) in the flexible carbon cloth (CC) substrate via a low-cost drop-coating method. Each CF in the CC provided a one-dimensional electron transfer core, and the wrapped BN/s-PT composite film functioned as the mesoporous electro-catalytic shell. Compared to pristine BN and pristine s-PT electrodes, the electrochemical and impedance performances of the BN/s-PT composite film were incredibly enhanced because of the synergetic effect of the BN nanoparticle and the s-PT binder; the former offered a large active surface area and a high intrinsic heterogeneous rate constant, and the latter formed fast electron transfer matrices. With a proper BN weight percentage among BN/s-PT solutions, the best DSSC coupling with a BN/s-PT composite counter electrode exhibited a good cell efficiency (η) of 9.21% at 1 sun, showing a great potential to substitute the expensive platinum (8.11%). At the dim light environment (i.e., T5 fluorescent illumination), the DSSC reached attractive η′s of 21.02% (6000 lux), 19.52% (3000 lux), and 17.48% (1000 lux).

Recent Advances on Pt-Free Electro-Catalysts for Dye-Sensitized Solar Cells

“… ( a ) The sketch of the process from ZIF-7 to ZIF-derived materials [ 86 ]. ( b ) Sketch of the electron transfer phenomenon in BN/s-PT-50 electrode [ 87 ]. ( c ) The fabrication process of a dye-sensitized solar cells with the Bi 2 MoO 6 /CNFs composite [ 89 ].…”

“… SEM images of ( a ) ZIF-ZnSe-NC-11 wt% [ 86 ], ( b ) BN/s-PT-50 [ 87 ], and ( c ) Bi 2 MoO6/CNFs [ 89 ]. ( d ) The TEM image of Bi 2 MoO 6 /CNFs [ 89 ].…”

“…Chen et al obtained a boron nitride/sulfonated poly(thiophene-3-[2-(2-methoxyethoxy)ethoxy]-2,5-diyl) (denoted as BN/s-PT) composite electrocatalyst by means of physical mixing [ 87 ]. The BN/s-PT-30, BN/s-PT-40, BN/s-PT-50, BN/s-PT-60, and BN/s-PT-70 contained the BN/s-PT with a weight percentage of 30, 40, 50, 60, and 70, respectively.…”

Novel Architecture of Indoor Bifacial Dye‐Sensitized Solar Cells with Efficiencies Surpassing 25% and Efficiency Ratios Exceeding 95%

“…Usually, the cells using a I − /I 3 − redox system have a relatively lower conversion efficiency due to their lower open‐circuit voltage ( V oc ) in comparison to those of cobalt redox‐couple systems. [ 10–13 ] In spite of this weakness, various new dyes and sensitization systems have been developed to overcome this shortage. Presently, efficiencies over 25% have been achieved using the I − /I 3 − redox system.…”

Polyaniline/Ag2S–CdS Nanocomposites as Efficient Electrocatalysts for Triiodide Reduction in Dye-Sensitized Solar Cells

“…Moreover, Pt-based counter electrodes generally undergo corrosion mediated by the iodine liquid electrolyte, resulting in DSSCs having low stability [5]. Therefore, many alternative materials have been studied as counter electrodes, including conducting polymers [6,7], carbon-based nanocomposites [8][9][10][11][12], and transition metal oxides, nitrides, carbide, selenides, and sulfides [13][14][15][16][17][18][19][20][21].…”