Enhanced visible light absorption and reduced charge recombination in AgNP plasmonic photoelectrochemical cell

Su, Buda; Shafie, Suhaidi; Rashid, Suraya Abdul; Jaafar, Haslina; Sharif, Noor Fadzilah Mohamed

doi:10.1016/j.rinp.2017.07.009

“…The Schottky barrier results in the storage of electrons which are subjected to charge-equilibration with the photo-excited semiconductor, thereby driving the Fermi level towards increasingly negative potentials 101 . This results in an electron sink that inhibits recombination processes in the dye-sensitized photoanode [102][103][104] .…”

Section: Performance Characteristics Of the Plasmonic Solar Cells Cumentioning

confidence: 99%

Plasmonic enhancement of betanin-lawsone co-sensitized solar cells via tailored bimodal size distribution of silver nanoparticles

D

¹

,

Pesala

²

2020

Sci Rep

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natural pigment-based photosensitizers are an attractive pathway for realizing low cost and environmentally friendly solar cells. Here, broadband light-harvesting is achieved using two natural pigments, betanin and lawsone, absorbing in the green and blue region of the solar spectrum respectively. the use of bimodal size distribution of Agnps tailored for each of the pigments to further increase their efficiency is the key feature of this work. This study demonstrates a significant enhancement in current-density, voltage, and efficiency by 20.1%, 5.5%, and 28.6% respectively, in a betanin-lawsone co-sensitized solar cell, via plasmonic enhancement using silver nanoparticles (Agnps). the optimum sizes of the nanoparticles have been calculated by studying their optical response and electric field profiles using Finite Difference Time Domain (FDTD) simulations, aimed at matching their resonant wavelengths with the absorption bands of the dyes. Simulations show that AgNPs of diameters 20 nm and 60 nm are optimum for enhanced absorption by lawsone and betanin respectively. The FDTD simulations of the plasmonic photoelectrodes demonstrated 30% and 15% enhancement in the power absorption by betanin and lawsone at the LSPR peaks of the 60 nm and 20 nm AgNPs respectively. An optimum overall concentration of 2% (v/v) and a ratio of 4:1 (20 nm:60 nm) of the bimodal distribution of the AgNPs, was determined for incorporation in the photoanodes. An average efficiency of 1.02 ± 0.006% was achieved by the betanin-lawsone co-sensitized solar cell with the bimodal distribution of AgNPs, compared to 0.793 ± 0.006% achieved by the non-plasmonic solar cell of otherwise identical configuration. Electrochemical impedance spectroscopy confirmed that the incorporation of the bimodal distribution of Agnps in the solar cells also enabled enhanced electron lifetime and reduced recombination compared to the non-plasmonic counterpart, thereby improving the charge transfer. the plasmonic enhancement methodology presented here can be applied to further improve the efficiency of other natural dye-sensitized solar cells. Since the seminal work in 1991 by O'Regan and Gratzel on Dye-Sensitized Solar Cells (DSSCs) 1 , immense interest has been directed towards their development in the last two decades. Owing to their inexpensive and facile processing requirements, DSSCs are becoming increasingly popular as an emerging photovoltaic technology 2-4. State-of-the-art DSSCs, which have achieved maximum efficiencies of 11.9% 5 , widely use metal-based dyes as the photosensitizer. Although these dyes are highly efficient sensitizers that effectively capture the entire visible spectrum, they employ rare metals such as ruthenium or osmium which require elaborate synthetic procedures. Moreover, they are expensive and toxic to the environment, making their disposal a problem. Therefore, natural pigments derived from plant sources, which are environment-friendly and inexpensive 6,7 , have come to the forefront as alternative photosensitizers. Several groups 8,...

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“…Ag + also acted as a trap site for excited electrons, giving rise to electron-hole separation. In addition, Ag + doping enhanced charge transport, prolonged the lifetime of electron-hole pairs, and reduced the charge recombination [39][40][41][42]. As a result, Ag + could be adopted for photocatalytic reduction process to improve NO − 3 removal.…”

mentioning

confidence: 99%

Effects of Initial Nitrate Concentrations and Photocatalyst Dosages on Ammonium Ion in Synthetic Wastewater Treated by Photocatalytic Reduction

Rojviroon

¹

,

Sirivithayapakorn

²

,

Rojviroon

³

et al. 2020

International Journal of Photoenergy

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Ammonium ( NH 4 + ) is an undesirable by-product of photocatalytic nitrate ( NO 3 − ) reduction since it is harmful to aquatic life once it converts into ammonia (NH3). This research investigated the removal efficiency of NO 3 − and for the first time quantified the relationships of initial nitrate concentrations ([ NO 3 − ]0) and photocatalyst dosages on the remaining ammonium ( NH 4 + ) in synthetic wastewater using photocatalytic reduction process with either nanoparticle titanium dioxide (TiO2) or 1.0%Ag-TiO2 under Ultraviolet A (UVA). The experiments were systematically carried out under various combinations of [ NO 3 − ]0 (10, 25, 50, 80, and 100 mg-N/L) and photocatalyst dosages (0.1, 0.5, 1.0, and 2.0 g). The NO 3 − removal efficiency of both photocatalysts was 98.96-99.98%, and the catalytic selectivity products were nitrogen gas (N2), nitrite ( NO 2 − ), and NH 4 + . Of the two photocatalysts under comparable experimental conditions, 1.0%Ag-TiO2 provided better NO 3 − removal efficiency. For both photocatalysts, the remaining NH 4 + was predominantly determined by [ NO 3 − ]0; higher [ NO 3 − ]0 led to higher NH 4 + . Multiple linear regression analysis confirmed the dominant role of [ NO 3 − ]0 in the remaining NH 4 + . The photocatalyst dosage could play an essential role in limiting NH 4 + in the treated wastewater, with large variation in [ NO 3 − ]0 from different sources.

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“…The comprehensive parameters are tabulated in Table 5. The short circuit current density Jsc of GO72-TiO 2 nanocomposite could achieve double than that of mesoporous TiO 2 (from 8.02 mA/cm 2 to 14.78 mA/cm 2 ), and the photoconversion efficiency (PCE) significantly increases from 2.96% to 6.25% (~111% increased PCE), which is probably attributed to the enhancement of photon loading absorption under visible light condition [24]. In other words, GO72 can be used as charge carrier facilitator agent to allow frequent flow of electrons from the conduction band (CB) of TiO 2 to the transparent conducting oxide (TCO).…”

Section: Resultsmentioning

confidence: 96%

An investigation of the stirring duration effect on synthesized graphene oxide for dye-sensitized solar cells

Yau

¹

,

Low

²

,

Khe

³

et al. 2020

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This study investigates the effects of stirring duration on the synthesis of graphene oxide (GO) using an improved Hummers' method. Various samples are examined under different stirring durations (20, 40, 60, 72, and 80 h). The synthesized GO samples are evaluated through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The GO sample with 72 h stirring duration (GO72) has the highest dspacing in the XRD results, highest atomic percentage of oxygen in EDX (49.57%), highest intensity of oxygen functional group in FTIR spectra, and highest intensity ratio in Raman analysis (I D /I G = 0.756). Results show that GO72 with continuous stirring has the highest degree of oxidation among other samples. Electrochemical impedance spectroscopy analysis shows that GO72-titanium dioxide (TiO 2) exhibits smaller charge transfer resistance and higher electron lifetime compared with the TiO 2-based photoanode. The GO72 sample incorporating TiO 2 nanocomposites achieves 6.25% photoconversion efficiency, indicating an increase of more than twice than that of the mesoporous TiO 2 sample. This condition is fully attributed to the efficient absorption rate of nanocomposites and the reduction of the recombination rate of TiO 2 by GO in dye-sensitized solar cells.

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Enhanced visible light absorption and reduced charge recombination in AgNP plasmonic photoelectrochemical cell

Cited by 30 publications

References 28 publications

Plasmonic enhancement of betanin-lawsone co-sensitized solar cells via tailored bimodal size distribution of silver nanoparticles

Plasmonic enhancement of betanin-lawsone co-sensitized solar cells via tailored bimodal size distribution of silver nanoparticles

Effects of Initial Nitrate Concentrations and Photocatalyst Dosages on Ammonium Ion in Synthetic Wastewater Treated by Photocatalytic Reduction

An investigation of the stirring duration effect on synthesized graphene oxide for dye-sensitized solar cells

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