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Precious platinum counter electrode (CE) has been an economic burden for future commercialization of dye-sensitized solar cells (DSSCs). Low-platinum alloy CE catalysts are promising in bringing down the solar cell cost without reducing photovoltaic performances. We present here a facile strategy of fabricating ZnO nanorods assisted platinum-nickel (PtNi) alloy microtube CEs for liquid-junction DSSCs. By adjusting the concentration of zinc precursors, the ZnO nanostructures and therefore PtNi alloys are optimized to maximize the electrocatalytic behaviors toward triiodide reduction reaction. The maximal power conversion efficiency is determined as high as 8.43% for liquid-junction DSSC device with alloyed PtNi microtube CE synthesized at 75 mM Zn(NO 3 ) 2 aqueous solution, yielding a 32.8% enhancement in cell efficiency in comparison with the solar cell from pristine platinum electrode. Moreover, the dissolution resistance and charge-transfer ability toward redox couples have also been markedly enhanced due to competitive dissolution reactions and alloyed effects. [ABSTRACT FROM AUTHOR]

Creation of transparent counter electrode (CE) electrocatalysts for bifacial dye-sensitized solar cells (DSSCs) is a persistent objective for reducing cost of photovoltaic conversion. We present here the experimental realization of highly transparent CuSe CEs by a mild solution method for liquid-junction bifacial DSSCs. The resultant CuSe CEs show superior electrocatalytic activity toward I 3 − reduction reaction. By optimizing the pH values in synthesizing CuSe electrodes, the maximal front efficiency of 6.21% and rear efficiency of 4.72% are recorded on the corresponding bifacial DSSC. Both catalytic activity and photovoltaic performances can be further elevated by alloying CuSe with Co or Fe, yielding promising efficiencies of 7.81% and 5.38% under front and rear irradiations, respectively. [ABSTRACT FROM AUTHOR]

Creation of cost-effective and platinum-free counter electrodes (CEs) is persistent for developing advanced dye-sensitized solar cells (DSSCs). We present here the fabrication of conducting polymers such as polyaniline (PANi), polypyrole (PPy), or poly(3,4-ethylenedioxythiophene) (PEDOT) intercalated reduced graphene oxide (rGO) CEs on flexible Ti foil or polyethylene-terephthalate substrate for liquid-junction DSSC applications. The ration architecture integrates the high electron-conducting ability of graphene and good electrocatalytic activity of a conducting polymer into a single CE material. The preliminary results demonstrate that the resultant CEs follow an order of rGO/PPy > rGO/PANi > rGO/PEDOT > rGO. A maximal cell efficiency of 6.23% is determined on the optimized solar cell device, yielding 104.9% enhancement in comparison to rGO based device. [ABSTRACT FROM AUTHOR]

One of the challenges in developing advanced dye-sensitized solar cells (DSSCs) is the pursuit of cost-effective and robust counter electrodes (CEs). We present here the successful synthesis of binary Pt x M 100−x (M = Ni, Co, Fe) alloy nanostructures on Ti foil by a facile and environmental-friendly strategy for utilization as CEs in liquid-junction DSSCs. Due to the reasonable charge-transfer ability and excellent electrocatalytic activity, the resultant DSSC yields a promising power conversion efficiency (PCE) of 6.42% with binary Pt 0.28 Ni 99.72 CE in comparison with 6.18% for pristine Pt CE based device. The easy synthesis, cost-effectiveness, and good electrocatalytic property may help the Pt 0.28 Ni 99.72 nanostructure stand out as an alternative CE electrocatalyst in a DSSC. [ABSTRACT FROM AUTHOR]

Pursuit of cost-effective counter electrode (CE) electrocatalysts with no sacrifice of photovoltaic performances has been a persistent objective for advanced dye-sensitized solar cell (DSSC) platforms. Here we demonstrate the experimental realization of CE electrocatalysts from Cu@M@Pt (M = Fe, Co, Ni) coaxial alloy nanowires for efficient DSSCs. The reasonable electrocatalytic activity is attributed to work function matching of alloy CEs to potential of I − / I 3 − and redistribute the electronic structure on the Pt surface. In comparison with 8.48% for the Pt nanotube CE based DSSC, the solar cells yield power conversion efficiencies up to 8.21%, 7.85%, and 7.30% using Cu@Fe@Pt, Cu@Co@Pt, and Cu@Ni@Pt NWs, respectively. This work represents an important step forward, as it demonstrates how to make the CE catalyst active and to accelerate the electron transport from CE to electrolyte for high-efficiency but cost-effective DSSC platforms. [ABSTRACT FROM AUTHOR]

Pursuit of cost-effective counter electrode (CE) electrocatalysts with no sacrifice of photovoltaic performances has been a persistent objective for dye-sensitized solar cells (DSSCs). Here we demonstrate the galvanic replacement realization of cost-effective CEs from Fe@M (M = Pd, Pt) nanospheres for DSSCs. Due to the enhanced catalytic activity originated from compressive strain and extended surface in tuning the electronic structure of Pd (or Pt) shell along with competitive dissolution reaction of Fe with electrolyte, the cells with high durability display efficiencies of 8.74% and 7.22%. The impressive results along with simple synthesis highlight the potential application of Fe@M nanospheres in robust DSSCs. [ABSTRACT FROM AUTHOR]

Pursuit of a high efficiency and stability has been a persistent objective for quantum dot-sensitized solar cells (QDSCs). Here we launch a strategy of synthesizing graphene implanted polyacrylamide (PAAm-G) conducting gel electrolytes for quasi-solid-state QDSCs. With an aim of elevating the dosage of S 2− /S x 2− redox couples and therefore charge-transfer ability, both osmotic press across the PAAm-G and capillary force within the three-dimensional micropores are utilized as driving forces. A promising power conversion efficiency of 2.34% is recorded for the QDSCs by optimizing graphene dosage in the conducting gel electrolyte. The enhanced conversion efficiency of solar cell is attributed to the expanded catalytic area from counter electrolyte/electrolyte interface to both interface and the conducting gel electrolyte. [ABSTRACT FROM AUTHOR]

High power conversion efficiency and cost-effectiveness are two persistent objectives for dye-sensitized solar cell (DSSC). Electricity generation from either front or rear side of a bifacial DSSC has been considered as a facile avenue of bringing down the cost of solar-to-electric conversion. Therefore, the fabrication of a transparent counter electrode (CE) with a high electrocatalytic activity is a prerequisite to realize this goal. We present here the feasibility of utilizing transparent cobalt selenide (Co–Se) binary alloy counter electrode for bifacial DSSC application, in which binary Co–Se alloy electrode is synthesized by a mild solution strategy and the cell device is irradiated by either front or rear side. Due to the high optical transparency, charge-transfer ability, and electrocatalytic activity, maximum front and rear efficiencies of 8.30% and 4.63% are recorded under simulated air mass 1.5 (AM1.5) irradiation, respectively. The impressive efficiency along with fast start-up, multiple start capability, and simple preparation highlights the potential application of cost-effective and transparent Co–Se alloy CE in robust bifacial DSSCs. [ABSTRACT FROM AUTHOR]

Pursuit of cost-effective and efficient counter electrodes (CEs) is a persistent objective for dye-sensitized solar cells (DSSCs). We present here the design of transparent Fe–Se nanoporous alloy CEs for bifacial DSSC applications. Due to the superior charge-transfer ability for I − /I 3 − redox couples, electrocatalytic reduction toward I 3 − species, and optical transparency in visible-light region, the bifacial DSSC with FeSe alloy electrode yields maximum front and rear efficiencies of 9.16% and 5.38%, respectively. A fast start-up, high multiple start capability, and good stability of the FeSe alloy CE demonstrate the potential applications in driving solar panels. The impressive efficiency along with simple preparation of the cost-effective Fe–Se nanoporous alloy CEs highlights their potential application in robust bifacial DSSCs. [ABSTRACT FROM AUTHOR]

Elevation of power conversion efficiency and reduction of electricity-generation cost have been two persistent objectives for quantum dot-sensitized solar cells (QDSSCs). Here we report a bifacial QDSSC structure having impressive power conversion efficiencies of 2.11% and 1.28% for front and rear irradiations, respectively. The device comprises a CdS-sensitized TiO 2 anode, a transparent cobalt selenide (Co–Se) counter electrode (CE), and a liquid electrolyte containing S 2− /S n 2− redox couples. Due to high optical transparency of the binary Co–Se alloy CE, incident light can penetrate the QDSSC from either front or rear side for electron excitation. A fast start-up and modest photocurrent stability are determined in the bifacial QDSSCs due to the high electron transfer kinetics in CdS-sensitized TiO 2 photoanode and electrocatalytic kinetics in Co–Se CE. [ABSTRACT FROM AUTHOR]

Pursuit of a high power conversion efficiency and reduction of electricity-generation cost has been a persistent objective for quantum dot-sensitized solar cells (QDSSCs). We present here the fabrication of a QDSSC comprising a nanoflower-structured CdS anode, a liquid electrolyte having S 2− /S n 2− redox couples, and a transparent CoSe counter electrode. Nanoflower-structured CdS anodes are prepared by a successive ionic layer adsorption and reaction (SILAR) method and subsequently hydrothermal strategy free of any surfactant or template. The CdS nanoparticles synthesized by a SILAR method act as “seed crystal” for growth of CdS nanoflowers. The average electron lifetime is markedly elevated in nanoflower-structured CdS anode in comparison with CdS nanoparticle or nanoporous CdS microsphere anode. Herein, we study the effect of synthesis method on CdS morphology and solar cell's photovoltaic performance, showing a power conversion efficiency of 1.67% and 1.17% for nanoflower-structured CdS QDSSC under front and rear irradiations, respectively. [ABSTRACT FROM AUTHOR]

Enhancement of light harvest for dye excitation is a persistent objective in dye-sensitized solar cell (DSSC). We present here the fabrication of titanium dioxide/calcium fluoride (TiO 2 /CaF 2 ) photoanodes for efficient DSSC applications. Owing to the interference effect of incident light beams reflected from TiO 2 /CaF 2 and CaF 2 /electrolyte interfaces, the light intensity and therefore dye excitation have been markedly enhanced. The crystal structure and therefore photovoltaic performance are optimized by adjusting CaF 2 dosage. A maximum power conversion efficiency of 7.66% is measured from the DSSC employing TiO 2 /0.5 wt% CaF 2 nanocrystallite in comparison with 6.02% for the solar cell with pristine TiO 2 anode. [ABSTRACT FROM AUTHOR]

Alloy materials have established themselves as alternative electrocatalysts for electrochemical devices because of their cost-effectiveness, high conductivity, good electrocatalytic activity, and reasonable stability. Aiming at reducing fabrication cost without sacrificing power conversion efficiency of dye-sensitized solar cells (DSSCs), we report the feasibility of designing transparent and cost-effective Fe–Se alloy counter electrodes for bifacial DSSCs. Due to the rapid charge transfer ability and electrocatalytic activity, maximum front and rear efficiencies of 7.64% and 4.95% are measured for the DSSC with FeSe alloy electrode in comparison with 6.97% and 3.56% from Pt-based solar cell. The impressive results along with simple synthesis highlight the potential application of Fe–Se alloys in robust bifacial DSSCs. [ABSTRACT FROM AUTHOR]

Storage of liquid electrolyte has been a persistent objective for liquid-state flexible dye-sensitized solar cells (DSSCs). We present here the feasibility of rear-irradiated flexible DSSC comprising of groove stored dye-sensitized TiO 2 on a Ti foil and conductive plastic supported transparent cobalt selenide alloy counter electrode. After being injected into the groove, the liquid electrolyte containing I − /I 3 − redox couples can be well sealed. The flexible cells are optimized by adjusting groove depth and stoichiometry of cobalt selenide electrodes, generating a maximum power conversion efficiency of 7.52% under one sun irradiation. The research demonstrates some new insights on how to improve liquid electrolyte retention and elevate photovoltaic performances of flexible DSSCs. [ABSTRACT FROM AUTHOR]

Enhancement of power conversion efficiency has been a long-term objective for dye-sensitized solar cells (DSSCs). In the current work, mesoporous TiO 2 anodes are synthesized by a gel-hydrothermal method using polyvinylpyrrolidone (PVP) as a pore-forming agent in order to elevate the dye loading, incident light illumination for dye excitation as well as electron transportation along conducting channels from TiO 2 nanoparticles. In comparison with dense TiO 2 anode, the dye illumination is also significantly enhanced, resulting in an increased photoelectron density on conduction band of TiO 2 . The photovoltaic performances are optimized by adjusting PVP dosage in synthesizing mesoporous TiO 2 anode. An impressive power conversion efficiency of 9.86% is recorded under one sun illumination. The power conversion efficiency is increased by ∼53.8% in comparison with the dense TiO 2 anode based DSSC. The high conversion efficiency in combination with simple preparation demonstrates the potential use of the approach in designing efficient DSSCs. [ABSTRACT FROM AUTHOR]

Abstract: Liquid electrolytes containing redox species have been widely used in dye-sensitized solar cells (DSSCs), whereas the volatility of organic solvents has been a tremendous obstacle for their commercial application. To assemble durable DSSCs, here we report the synthesis of full-ionic liquid electrolyte, in which 1-butyl-3-methylimidazolium nitrate is employed as solvent and 1-methyl-3-propylimidazolium iodide is iodide source. Using the imbibition performance of amphiphilic poly(acrylic acid/gelatin) [poly(AA/GR)] and poly(acrylic acid/cetyltrimethyl ammonium bromide) [poly(AA/CTAB)] matrices, full-ionic liquid electrolytes are imbibed into three-dimensional framework of poly(AA/GR) or poly(AA/CTAB) to form stable gel electrolytes. Room-temperature ionic conductivities as high as 17.82 and 18.44 mS cm−1 are recorded from full-ionic liquid imbibed poly(AA/GR) and poly(AA/CTAB) gel electrolytes, respectively. Promising power conversion efficiencies of 7.19% and 7.15% are determined from their DSSC devices in comparison with 6.55% and 6.12% from traditional acetonitrile-based poly(AA/GR) and poly(AA/CTAB) gel electrolytes, respectively. The new concept along with easy fabrication demonstrates the full-ionic liquid electrolytes to be good alternatives for robust gel electrolytes in quasi-solid-state DSSCs. [Copyright &y& Elsevier]

Abstract: Three-dimensional (3D) gel electrolytes are versatile in elevating encapsulation of liquid electrolyte in dye-sensitized solar cells (DSSCs), however, the poor contact at gel electrolyte/Pt counter electrode interface is unfavorable in electrocatalyzing triiodide ions. In the current work, we report the multifunctions of graphene, graphene oxide, or nanographite incorporated microporous poly(acrylic acid)-cetyltrimethylammonium bromide (PAA-CTAB) conducting gel electrolytes in both sealing liquid electrolyte and conducting refluxed electrons (electrons from external circuit to Pt counter electrode) into 3D framework of the conducting gel electrolyte, aiming at elevating liquid electrolyte content in per unit volume of gel electrolyte, increasing electrocatalytic area toward triiodide ions and diminishing charge-transfer resistance. The electrical and electrochemical performances of the resultant conducting gel electrolytes are thoroughly characterized. Light-to-electric power conversion efficiencies of 7.06%, 6.35%, and 6.17% are determined from DSSCs using graphene, graphene oxide, and nanographite incorporated PAA-CTAB conducting gel electrolytes in comparison with 6.07% from pure PAA-CTAB based DSSC. [Copyright &y& Elsevier]

Abstract: With an aim of enhancing the light-to-electric power conversion efficiency of dye-sensitized solar cell (DSSC), here we synthesize PtRu nanofiber alloys using a low-temperature hydrothermal technique which are employed as counter electrodes (CEs) for DSSCs. Owing to the good electrical conduction and electrocatalysis, light-to-electric power conversion efficiencies of PtRu-based DSSCs have been elevated in comparison with that of Pt CE based DSSC. The DSSC employing PtRu3 alloy CE gives a power conversion efficiency of 6.80% in comparison with 6.17% from Pt-based DSSC. The reasonable conversion efficiency, simple preparation, and scalability demonstrate the potential use of PtRu alloys in efficient DSSCs. [Copyright &y& Elsevier]

Abstract: Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, high efficiency, good durability, and easy fabrication. However, enhancement of power conversion efficiency and high cost of Pt counter electrode are still significant issues in commercial application of DSSCs. Herein, pyrrole–single wall nanotube (pyrrole–SWCNT) complexes are pioneerly synthesized by a reflux technique and subsequently in-situ polymerized and employed as counter electrodes (CEs) for DSSCs. Different from traditional polypyrrole/SWCNT (PPy/SWCNT) composites, the resultant PPy–SWCNT complexes are expected to fulfill the good electrical-conduction of SWCNT and electrocatalytic behaviors of PPy in accelerating electrochemical activity and charge transfer owing to the covalent bond between PPy (N atoms) and SWCNT (C atoms). The DSSCs employing PPy–SWCNT complex CEs exhibit significantly enhanced photovoltaic performances, in which a promising power conversion efficiency of 8.30% is obtained from PPy–2 wt‰ SWCNT complex CE in comparison with 6.31% from PPy-only CE. The high conversion efficiency, rapid charge-transfer in combination with simple preparation, relatively low cost, and scalability demonstrates the potential use of PPy–SWCNT complexes in robust DSSCs. [Copyright &y& Elsevier]

Abstract: With an aim of significantly enhancing charge-transfer ability of counter electrodes and therefore photovoltaic performances of dye-sensitized solar cells (DSSCs), here we pioneerly report the complexation of polyaniline (PANi) and graphene as well as their employment as counter electrodes (CEs) in efficient DSSCs. Owing to the covalent bond between PANi (N atoms) and graphene (C atoms), charge transfer kinetics is dramatically elevated, which can be confirmed by the enhancement on electrocatalytic activity toward triiodides and a decrease in charge-transfer resistance. A power conversion efficiency of 7.70% is determined from DSSC using PANi−8 wt‰ graphene complex CE in comparison with 6.40% from pure PANi CE-based DSSC. The high conversion efficiency, facile charge-transfer in combination with simple preparation, relatively low cost, and scalability demonstrates the potential use of PANi−graphene complexes in robust DSSCs. [Copyright &y& Elsevier]

Abstract: With an aim of elevating liquid electrolyte loading, ionic conductivity, and electrocatalytic activity of gel electrolyte toward triiodides, freeze-dried microporous poly(acrylic acid)–poly(ethylene glycol) (PAA–PEG) matrix is employed to uptake conducting polymers, such as polyaniline (PANi) and polypyrrole (PPy). An ionic conductivity of 19.18 mS cm−1 at 65 °C is obtained from PAA–PEG/PANi conducting gel electrolyte which is nearly similar to 19.22 mS cm−1 from pure liquid electrolyte. The conducting polymers can form interconnected channels within insulating microporous PAA–PEG matrix, therefore, the reduction reaction of triiodide ions in the dye-sensitized solar cells (DSSCs) can be extended from Pt/gel electrolyte interface to both interface and three-dimensional framework of microporous conducting gel electrolyte. The resultant DSSCs from PAA–PEG/PANi and PAA–PEG/PPy conducting gel electrolytes display power conversion efficiencies of 7.12% and 6.53%, respectively, which are much higher than 5.02% from pure PAA–PEG-based DSSC. The new concept along with easy fabrication promises the microporous conducting gel electrolytes to be good alternatives in efficient quasi-solid-state DSSCs. [Copyright &y& Elsevier]

Abstract: Proton exchange membrane (PEM), transferring protons from anode to cathode, is a key component in a PEM fuel cell. In the current work, a new class of PEMs are synthesized benefiting from the imbibition behavior of three-dimensional (3D) polyacrylamide-graft-chitosan (PAAm-graft-chitosan) frameworks to H3PO4 aqueous solution. Interconnected 3D framework of PAAm-graft-chitosan provides tremendous space for holding proton-conducting H3PO4. The highest anhydrous proton conductivity of 0.13 S cm−1 at 165 °C is obtained. A fuel cell using a thick membrane as a PEM showed a peak power density of 405 mW cm−2 with O2 and H2 as the oxidant and fuel, respectively. Results indicate that the interconnected 3D framework provides superhighway for proton conduction. The valued merits on anhydrous proton conductivity, huge H3PO4 loading, and easy synthesis promise the new membranes to be good alternatives as high-temperature PEMs. [Copyright &y& Elsevier]

Abstract: Volatility of organic solvent in liquid electrolyte has been tremendous obstacle for its application in dye-sensitized solar cells (DSSCs), here we designed an ionic liquid-imbibed polymer gel electrolyte using 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as solvent, 1-methyl-3-propylimidazolium iodide (MPII) as iodine source, and amphiphilic poly(hydroxyethyl methacrylate/glycerol) [poly(HEMA/GR)] as a placeholder. As an amphiphilic matrix, poly(HEMA/GR) material can swell in ionic liquid electrolyte to form a stable gel, benefiting from its extraordinary absorption. The imbibed ionic liquid electrolyte is stored into interconnected poly(HEMA/GR) framework. Resultant quasi-solid-state electrolyte is honored with high ionic conductivity (14.29 mS cm−1) at room temperature and good retention. The ionic liquid-imbibed poly(HEMA/GR) gel electrolyte-based DSSC gives an overall light-to-electric conversion efficiency of 7.15%. The new concept along with easy fabrication promises the ionic liquid-imbibed gel electrolytes good alternatives in efficient DSSCs. [Copyright &y& Elsevier]

Abstract: Amphiphilic poly(hydroxyethyl methacrylate/cetytrimethylammonium bromide) [poly(HEMA/CTAB)] gel with a three-dimensional framework is successfully fabricated and employed to integrate with polyaniline (PANi). The resultant PANi imbibed poly(HEMA/CTAB) gel electrolyte provides space for holding I−/I3 −, giving a similar conduction mechanism and ionic conductivity to that of liquid system. The caged liquid electrolyte cannot leak from the three-dimensional framework of gel electrolyte under pressure of cell assembly. Fourier transform infrared spectra, X-ray diffraction patterns, cyclic voltammograms as well as electrochemical impedance spectra are employed to evaluate the molecular structure, crystallinity, and the electrochemical behaviors, showing that the combination of PANi with poly(HEMA/CTAB) results in an enhanced ionic conduction, lowered charge-transfer resistance, and extended electrocatalytic reaction toward I−/I3 − redox couples from Pt/gel electrolyte interface to both interface and three-dimensional framework of the gel electrolyte. The resultant quasi-solid-state dye-sensitized solar cells based on PANi imbibed poly(HEMA/CTAB) gel electrolyte shows a light-to-electric conversion efficiency of 6.68%, which higher than that from PANi-free poly(HEMA/CTAB). [Copyright &y& Elsevier]

Abstract: This paper reports the first study that investigates H3PO4-imbibed polyacrylamide/poly(vinyl alcohol) (PAM/PVA) semi-interpenetrating polymer network (semi-IPN) hydrogel as a high-temperature proton exchange membrane (PEM). The extraordinary ability of the PAM/PVA hydrogel to absorb a large quantity of aqueous solution is fully utilized to achieve a high H3PO4 loading, resulting in high proton conductivity membranes. The anhydrous proton conductivity of a PAM/PVA semi-IPN hydrogel loaded with 73.5 wt% H3PO4 reaches 0.0525 S cm−1 at 183 °C in dry air. A fuel cell using the thick-film PAM/PVA hydrogel exhibits a peak power density of 0.225 W cm−2 at 183 °C with pure O2 and H2 as the oxidant and fuel, respectively. The synthesized membrane also shows excellent acid retention under mechanical load and high humidity, a valued characteristic for high-temperature PEMs. These performance-ensuring properties paired with a low-cost synthesis approach demonstrate the new membrane to be a viable candidate as a high-temperature PEM. [Copyright &y& Elsevier]

Abstract: A separator is prepared based on natural and flexible eggshell membrane (ESM) for supercapacitor application. Morphology observation shows that the ESM is consisted of hierarchically ordered macroporous network. With a high decomposition temperature (>220°C), enough mechanical strength (σ max =6.59±0.48MPa, ɛ max =6.98±0.31%, respectively), and low water uptake and swelling property (<10%), ESM could be a promising candidate for supercapacitor separator. As expected, the supercapacitor with ESM separator exhibits outstanding electrochemical performances, such as low resistance, quick charge–discharge ability (τ is 4.76s), and good cyclic stability (92% retention after 10,000 cycles). However, the one with PE separator shows worse properties (high resistance, low specific capacitance, etc.). This research provides new insight into the preparation of natural, low-cost and high-performance separator for supercapacitor and other applications. [Copyright &y& Elsevier]

The preferred platinum counter electrode (CE) has been a burden for commercialization of dye-sensitized solar cell (DSSC) due to high expense and chemical corrosion by liquid electrolyte. In the current study, we have successfully realized the multistep deposition of platinum alloy CEs including PtNi, PtFe, and PtCo for liquid-junction DSSC applications. The preliminary results demonstrate that the enhanced electrochemical activities are attributable to high charge-transfer ability and matching work functions of the PtM (M = Ni, Fe, Co) alloy CEs to redox potential of I − /I 3 − electrolyte. The resultant DSSCs yield impressive power conversion efficiencies of 8.65%, 7.48%, and 7.08% with PtNi, PtFe, and PtCo CEs, respectively. On behalf of the competitive reactions between transition metals with liquid electrolyte, the PtM alloy CEs display enhanced long-term stability. [ABSTRACT FROM AUTHOR]

Pursuit of technological implementation with no sacrifice of photovoltaic performances has been a persistent objective for dye-sensitized solar cells (DSSCs). We launch here the experimental realization of a class of DSSCs consisting of polyaniline (PANi) incorporated TiO 2 anodes, PANi counter electrodes (CEs), and iodide doped PANi solid-state electrolytes. The PANi filled in photoanode can inject electrons for dye recovery, whereas the PANi CE fulfills the function of reducing triiodide into iodide ions. In particular, the solid PANi electrolyte has an ability of catalyzing triiodide species, shortening charge diffusion path length, and recovering dye molecules at anode/electrolyte interface. The photovoltaic performances are optimized by adjusting assembly process and lithium iodide dosage, yielding a maximum efficiency as high as 3.1% in the resultant DSSC device accompanied with fast start-up, multiple start/stop cycling, and good stability under persistent irradiation. [ABSTRACT FROM AUTHOR]

Exploration of cost-effective counter electrodes (CEs) and enhancement of power conversion efficiency have been two persistent objectives for dye-sensitized solar cells (DSSCs). In the current work, polyaniline–multiwalled carbon nanotube (PANi–MWCNT) complexes are synthesized by a reflux method and employed as CE materials for bifacial DSSCs. Owing to the high optical transparency of PANi–MWCNT complex CE, the incident light from rear side can compensate for the incident light from TiO 2 anode. The charge-transfer ability and electrochemical behaviors demonstrate the potential utilization of PANi–MWCNT complex CEs in robust bifacial DSSCs. The electrochemical properties as well as photovoltaic performances are optimized by adjusting MWCNT dosages. A maximum power conversion efficiency of 9.24% is recorded from the bifacial DSSC employing PANi–8 wt‰ MWCNT complex CE for both irradiation, which is better than 8.08% from pure PANi CE. [ABSTRACT FROM AUTHOR]

Enhancement in power conversion efficiency is a persistent pursuit for solid-state dye-sensitized solar cells (DSSCs). We report an experimental strategy of synthesizing I − /I 3 − doped 3-hydroxypropionitrile/polyaniline (HPN/PANi) solid electrolytes, aiming at expanding I 3 − reduction reaction from electrolyte/counter electrode interface to solid electrolyte system and shortening the charge diffusion path length. The DSSC with HPN/1.0 wt% PANi shows an efficiency of 3.70% in comparison to 1.49% from the cell with pristine HPN. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, cost-effectiveness, relatively high efficiency, and easy fabrication. However, the reduction of fabrication cost without sacrifice of power conversion efficiencies of the DSSCs is a golden rule for their commercialization. Here we design a new binary ruthenium selenide (Ru–Se) alloy counter electrodes (CEs) by a low-temperature hydrothermal reduction method. The electrochemical behaviors are evaluated by cyclic voltammogram, electrochemical impedance, and Tafel measurements, giving an optimized Ru/Se molar ratio of 1:1. The DSSC device with RuSe alloy CE achieves a power conversion efficiency of 7.15%, which is higher than 5.79% from Pt-only CE based DSSC. The new concept, easy process along with promising results provide a new approach for reducing cost but enhancing photovoltaic performances of DSSCs. [ABSTRACT FROM AUTHOR]

Abstract: Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, low fabrication cost, relatively high power conversion efficiency, good durability, and easy assembly. However, the commercial application of DSSCs has been hindered by the high expenses of counter electrodes (CEs). With an aim of significantly enhancing the light-to-electric power conversion efficiency, here we pioneerly synthesize CoPt alloys using an electrochemically codeposition technique which are employed as CEs for efficient DSSCs. Owing to the rapid charge transfer, electrical conduction, and electrocatalysis, power conversion efficiencies of CoPt alloy CE-based DSSCs have been markedly elevated in comparison with that of the DSSC from Pt-only CE. The DSSC employing CoPt0.1 alloy CE gives an impressive power conversion efficiency of 9.59%, which is much higher than 6.86% from conversional Pt-based DSSC. The high conversion efficiency, low cost in combination with simple preparation, and scalability demonstrates the potential use of CoPt alloy CEs in efficient DSSCs. [Copyright &y& Elsevier]

Abstract: The extension of electrocatalytic reaction area toward iodides is expected to significantly accelerate the recovery of redox couples and therefore photovoltaic performances of quasi-solid-state dye-sensitized solar cells (DSSCs). To improve the cell properties of DSSC, a three-dimensional polypyrrole imbibed poly(hydroxyethyl acrylate)/poly(ethylene glycol) gel electrolyte has been successfully synthesized using the adsorption behavior of amphiphilic poly(hydroxyethyl acrylate)/poly(ethylene glycol) to pyrrole monomers. Resultant gel electrolyte is thoroughly characterized by spectral analysis and electrochemical characterizations. In comparison with pure poly(hydroxyethyl acrylate)/poly(ethylene glycol) gel electrolyte, the incorporation of electron-conducting polypyrrole shows enhanced physicochemical properties. Interconnected micropores within the gel electrolyte provides space for holding I−/I3 − liquid electrolyte, giving an ionic conductivity of 21.08 mS cm−1. The integration of polypyrrole on poly(hydroxyethyl acrylate)/poly(ethylene glycol) gives a higher electrocatalytic activity because of the extension of electrocatalytic reaction toward I−/I3 − couple from counter electrode/gel electrolyte interface to the three-dimensional framework of gel electrolyte. The resultant DSSC from polypyrrole imbibed poly(hydroxyethyl acrylate)/poly(ethylene glycol) gel electrolyte displays a light-to-electric conversion efficiency of 7.02% in comparison with 5.76% from pure poly(hydroxyethyl acrylate)/poly(ethylene glycol). The new concept along with easy fabrication promise the conducting polymer imbibed amphiphilic gel electrolytes good candidates in robust DSSCs. [Copyright &y& Elsevier]

Abstract The co-sensitization of mesoscopic TiO 2 anode is a promising solution to wide-spectra dye-sensitized solar cells (DSSCs) with improved power conversion efficiency. Quantum dots are featured with tunable bandgaps, small sizes and high absorption coefficients, therefore they are always combined with state-of-the-art organic dyes for co-sensitized solar cells. We present here the sonochemistry-assisted synthesis of hybrid black/red phosphorus quantum dots (BP/RPQDs) for DSSC applications. The preliminary results demonstrate that hybrid BP/RPQDs have prolonged recombination lifetime of photogenerated carriers and light-response from ultraviolet to visible and even near-infrared (NIR) region. Upon assembly into liquid-junction DSSCs, the devices with BP/RPQDs-only and BP/RPQDs-N719 co-sensitizer achieve efficiencies of 0.12% and 8.02% in comparison with 7.60% for N719-only solar cell. Using photofluorescent photoanode from mesoscopic TiO 2 and long-persistence phosphor (LPP), the new-typed DSSC presents persistent power generation performances after ceasing simulated sunlight irradiation. Graphical abstract Image 1 Highlights • Hybrid BP/RPQDs are made by a sonochemistry-assisted method. • The hybrid BP/RPQDs show wide light-response in light-harvesters of DSSCs. • BP/RPQDs-only solar cells show a PCE of 0.12%. • An efficiency as high as 8.02% is achieved for BP/RPQDs tailored DSSCs. [ABSTRACT FROM AUTHOR]

Abstract High-temperature supercapacitors with enhanced charge transportation and capacitances are promising to meet specific requirements for underhood automotive component, oil drilling, military and space applications. However, state-of-the-art supercapacitors are always operated at room temperature due to the thermal instability of the hydrous electrolytes and organic separators. Herein, we present the fabrication of a high-temperature supercapacitor tailored by a ceramic NiO/ZrO 2 separator. This supercapacitor has a working temperature up to 140 °C, a capacitance of 342 F g-1 at current density of 2 A g−1 and good cycling stability over 2000 cycles. The experimental realization of physical proof-of-concept high-temperature supercapacitors may provide new opportunities for markedly improving the capacity of energy storage systems. Graphical abstract Image 1 Highlights • The ceramic NiO/ZrO 2 membranes are made to replace polymer separators. • The ceramic membranes are applied for high-temperature supercapacitors. • A KOH glycerin solution is utilized as a high-temperature electrolyte. • The device yields a maximized capacitance up to 342 F g-1 at 140 °C. • The high-temperature supercapacitors are stable at 140 °C over 2000 cycles. [ABSTRACT FROM AUTHOR]

Abstract Interfacial charge recombination seriously drags efficiency enhancement of all-inorganic perovskite solar cells (PSCs) because of large energy-level differences. Although CsPbBr 3-x I x light-harvesters markedly reduce interfacial charge recombination, the long-term stability of solar cell devices is still unsatisfactory to meet practical requirements. Here we present the improved charge extraction by setting an intermediated energy-level at CsPbBr 3 /carbon interface with colorful CsSnBr 3-x I x quantum dots (QDs). The charge extraction is maximized by tuning Br:I ratio, yielding a power conversion efficiency as high as 9.13% for CsSnBr 2 I QDs-tailored CsPbBr 3 solar cell. Moreover, all the devices show high stability in 80%RH or 80 °C over 720 h. The interfacial decoration of all-inorganic perovskite solar cells by lead-free perovskite QDs provides new opportunities of enhancing solar cell efficiency and reducing environmental impacts. Highlights • PQDs with tunable bandgaps are synthesized to modify CsPbBr 3 /carbon interface. • An intermediate energy level is set at CsPbBr 3 /carbon interface to extract holes. • The electron-hole recommendation is markedly restricted. • A maximized PCE of 9.13% is achieved for the PQDs tailored inorganic PSC. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

The supercapacitor that can operate at high-temperature are promising for markedly increase in capacitance because of accelerated charge movement. However, the state-of-the-art polymer-based membranes will decompose at high temperature. Inspired by solid oxide fuel cells, we present here the experimental realization of high-temperature supercapacitors (HTSCs) tailored with porous ceramic separator fabricated by yttria-stabilized zirconia (YSZ) and nickel oxide (NiO). Using activated carbon electrode and supporting electrolyte from potassium hydroxide (KOH) aqueous solution, a category of symmetrical HTSCs are built in comparison with a conventional polymer membrane based device. The dependence of capacitance performance on temperature is carefully studied, yielding a maximized specific capacitance of 272 F g −1 at 90 °C for the optimized HTSC tailored by NiO/YSZ membrane. Moreover, the resultant HTSC has relatively high durability when suffer repeated measurement over 1000 cycles at 90 °C, while the polymer membrane based supercapacitor shows significant reduction in capacitance at 60 °C. The high capacitance along with durability demonstrates NiO/YSZ membrane tailored HTSCs are promising in future advanced energy storage devices. [ABSTRACT FROM AUTHOR]

Photovoltaics are promising solutions to energy crisis and environmental pollution problems. The dye-sensitized solar cells with mesoscopic structures have attracted growing interests because of zero emissions, easy fabrication, scalable materials and techniques, etc . However, the state-of-the-art dye-sensitized solar cells have narrow spectral absorption for photoelectric conversion and high electron-hole recombination rate under sunlight illumination. Therefore, it is a persistent object to make wide-spectral absorption and fast charge extraction solar cells for energy harvest in both solar and dark-light conditions. To address this issue, we present here experimental realization of a category of solar cells converting visible and near-infrared light into electricity by co-sensitizing photoanode with N719 dye and polyethylene glycol (PEG) modified carbon quantum dots (PEG- m -CQDs), arising from up-conversion and hole-transporting behaviors of PEG- m -CQDs as well as photofluorescence of green-emitting long persistence phosphors. The optimized solar cell yields maximized photoelectric conversion efficiencies of 9.89% and 25.81% under simulated sunlight (air mass 1.5, 100 mW cm −2 ) illumination and dark conditions, respectively. This work is far from optimization, but the physical proof-of-concept hybridized solar cell may markedly increase electricity generation time and total power output of photovoltaic platforms. [ABSTRACT FROM AUTHOR]

Abstract: A microporous hybrid polymer of poly(acrylic acid)/gelatin/polyaniline (PAA/Gel/PANI) is synthesized with a two-steps solution polymerization. Using this hybrid as polymer host, a gel-electrolyte with a high liquid absorbency of 16.45 (gg−1) and a high conductivity of 14.38mScm−1 is prepared, then a quasi-solid-state dye-sensitized solar cell (QS-DSSC) is assembled. The polymer host is characterized by scanning electron microscopy (SEM), the functional groups on the polymer are identified by Fourier transform infrared spectroscopy (FTIR) and the photovoltaic tests of the QS-DSSCs are carried out by measuring current–voltage (I–V) curves. The QS-DSSC with this hybrid gel-electrolyte achieves a light-to-electric energy conversion efficiency of 6.94%. [Copyright &y& Elsevier]

Inorganic cesium lead bromide (CsPbBr 3) perovskite solar cells (PSCs) have superior moisture- and thermal-stability in comparison with organic-specie or/and I-containing devices. However, the narrow-spectra absorption (<550 nm) arising from their large bandgap of 2.3 eV for CsPbBr 3 halide has markedly limited the further efficiency enhancement of corresponding inorganic device, therefore a great challenge is to broaden the light response range without sacrificing environmental tolerances. In this work, we constructively fabricate a CsPbBr 3 /bulk-heterojunction (organic J 61 -ITIC) photoactive layer to widen the optical absorption range of inorganic CsPbBr 3 based interlayer-free device. Arising from the broadened light response wavelength from 550 to 780 nm and precisely optimized crystal lattice by incorporating Rb+ into CsPbBr 3 film, the optimal device achieves a power conversion efficiency up to 10.34% under one sun illumination. Upon persistent attacks by heat of 80 °C (0% humidity) or 90% humidity (25 °C) over 40 days, the solar cell can still remain approximately 96% of initial efficiency, demonstrating the excellent stability for practical application. Image 1 • Organic bulk-heterojunction photoactive layer is integrated into inorganic CsPbBr 3 PSCs. • Alkalis ion Rb+ has been doped into inorganic CsPbBr 3 perovskite films. • The integrated CsPbBr 3 /bulk-heterojunction solar cell achieves a PCE of 10.34%. • The optimal device shows excellent long-term stability. [ABSTRACT FROM AUTHOR]