•CPs-GO/CNTs ternary composites have been prepared via one-step electrodeposition.•The composites show a GO supported CPs-coated CNTs ternary hybrid microstructure.•The capacitive nature of CPs-GO is ...promoted significantly by introducing CNTs.•CPs-GO/CNTs electrodes show high areal capacitance and excellent cycle stability.
Composite films of heterogeneous conducting polymers-coated graphene oxide/carbon nanotubes (CPs-GO/CNTs; CPs, PPy and PEDOT) have been fabricated via one-step electrochemical co-deposition. Scanning electron microscope and transmission electron microscopy characterizations indicate that the as-prepared CPs-GO/CNTs composites show a GO supported CPs-coated CNTs ternary hybrid microstructure. The electrochemical measurements including cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy tests manifest that the capacitive performances of CPs-GO electrodes are obviously promoted as the introduction of CNTs, and the PEDOT-GO/CNTs electrodes exhibit the more significantly improved electrochemical performances as the more CNTs introduced. Furthermore, the as-prepared PPy-GO/CNTs and PEDOT-GO/CNTs ternary composites achieve a high areal specific capacitance (142.2mFcm−2 and 99.0mFcm−2at 1.0mAcm−2, respectively), together with superior rate capability, and excellent cycle stability (maintain 97.3% and 99.2% of initial capacitance for 5000 cycles, respectively), which are essential for their applications in high-performance supercapacitor electrodes.
The emerging dye-sensitized solar cells, perovskite solar cells, and organic solar cells have been regarded as promising photovoltaic technologies. The device structures and components of these solar ...cells are imperative to the device's efficiency and stability. Polymers can be used to adjust the device components and structures of these solar cells purposefully, due to their diversified properties. In dye-sensitized solar cells, polymers can be used as flexible substrates, pore- and film-forming agents of photoanode films, platinum-free counter electrodes, and the frameworks of quasi-solid-state electrolytes. In perovskite solar cells, polymers can be used as the additives to adjust the nucleation and crystallization processes in perovskite films. The polymers can also be used as hole transfer materials, electron transfer materials, and interface layer to enhance the carrier separation efficiency and reduce the recombination. In organic solar cells, polymers are often used as donor layers, buffer layers, and other polymer-based micro/nanostructures in binary or ternary devices to influence device performances. The current achievements about the applications of polymers in solar cells are reviewed and analyzed. In addition, the benefits of polymers for solar cells, the challenges for practical application, and possible solutions are also assessed.
High performance dual function of polyaniline (PANI) with brachyplast structure is synthesized by using a two-step cyclic voltammetry (CV) approach onto the fluorinated tin oxide (FTO) glass ...substrate, which acts as the sensitizer and p-type hole-transporting material (p-HTM) for the all-solid-state perovskite-sensitized solar cell (ass-PSSC) due to its π–π* transition and the localized polaron. The ass-PSSC based on the PANI delivers a photovoltaic conversion efficiency of 7.34%, and reduces from 7.34% to 6.71% after 1000 h, thereby 91.42% of the energy conversion efficiency is kept, indicating the device has a good long-term stability.
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•Polyaniline with brachyplast structure was electropolymerized and characterized.•The polyaniline acted as the sensitizer and p-type HTM for the ass-PSSC.•The ass-PSSC delivered a photovoltaic conversion efficiency of 7.34%.•The ass-PSSC demonstrated a good long-term stability after 1000 h.
•This work reports a sensitive amperometric biosensor for carbamate.•The biosensor shows a detection limit of 0.15ngmL−1 for carbaryl detection.•The biosensor exhibits good reproducibility and ...stability.
This work describes a sensitive electrochemical biosensor for detection of carbamate pesticides based on immobilization of acetylcholinesterase (AChE) on the electrochemically inducing porous graphene oxide network (e-pGON) which is prepared by scanning the GO modified electrode using successive cyclic voltammetry method. The e-pGON effectively promotes the electron transfer rate and facilitates the access of substrates to the active centers. The as-prepared biosensor shows high affinity to acetylthiocholine (ATCl) with a Michaelis-Menten constant value of 0.45mmolL−1. Under optimum conditions, the inhibition of carbaryl is proportional to its concentration ranging from 0.3 to 6.1ng/mL. The detection limit is 0.15ng/mL. The developed biosensor exhibits good performance such as reproducibility and stability, thus providing a promising tool for the analysis of enzyme inhibitors.
A novel bifacial perovskite solar cell (PSC) is devised and prepared by using a highly transparent poly(3,4-ethylenedioxythiophene) (PEDOT) electrode. The PEDOT is used as the p-type ...hole-transporting material (HTM) due to the well matched band positions for the charge separation and transport. Moreover, the PEDOT layer can play a role of electron blocking layer at the CH3NH3PbI3/PEDOT interface to reduce the electron recombination rate because of its LUMO level is higher than that of the perovskite sensitizer. As a result, the bifacial PSC based on the PEDOT HTM yields front and rear efficiencies of 12.33% and 11.78% respectively, which are higher than those of the PSC without the PEDOT HTM (8.67% and 8.27% of the front and rear efficiencies). And the front efficiency is only decreased by 4.46% to the rear efficiency. These promising results highlight the potential application of the PEDOT in the cost-effective and transparent PSC, which could be used in the bifacial solar cell and tandem solar cell.
A novel bifacial PSC based on the highly transparent PEDOT HTM yields front and rear efficiencies of 12.33% and 11.78% respectively. The front efficiency is only decreased by 4.46% to rear efficiency. The PEDOT acts as a function of HTM to enhance the device performance due to the well matched band positions for the charge separation and transport. Moreover, the PEDOT can play a role of electron blocking layer at the CH3NH3PbI3/PEDOT interface to reduce the electron recombination rate owing to its LUMO level is higher than that of the perovskite sensitizer. Display omitted
•Efficiently bifacial PSC is prepared based on the highly transparent PEDOT HTM.•The bifacial PSC reaches 12.33% and 11.78% of the front and rear efficiencies.•The front efficiency is only decreased by 4.46% to rear efficiency.
A titanium (Ti) foil based perovskite solar cell (PSC) is devised and prepared by employing titanium dioxide nanowire (TNW) arrays and titanium dioxide nanoparticles (TNPs) on Ti foil substrates as ...the electron transporting layer (ETL). The TNW array is desirable for the PSC, since it can provide direct pathways for the rapid collection and transmission of photo-generated electrons. The Ti foil substrate has many advantages such as flexibility, low sheet resistance, and excellent mechanical stability. The sunlight illuminates through the highly transparent poly(3,4-ethylenedioxythiophene) (PEDOT) film on the indium doped tin oxide/polyethylene naphthalate (ITO/PEN) substrate. The transparent PEDOT electrode can be used as the hole transporting layer (HTL) due to the well matched band positions for charge separation and transport. As a result, the Ti foil based light-weight PSC with TNW arrays yields an efficiency of 13.07% with an active area of 1.00 cm 2 , which is higher than that of the PSC with TNPs (9.93%). These promising results highlight the potential application of the PEDOT and Ti foil in cost-effective, large-area, and flexible PSCs.
Graphite as a competitive anode material of potassium-ion batteries (KIBs) is currently frustrated by the poor cycling stability and rate performance. In this study, high-performance activated ...graphite that derives from low-grade microcrystalline graphite ore is fabricated through a facile KOH activation method and the following HF leaching. The effect of activation temperature (from 450 to 650 °C) on the physical parameters and K-storage performance of the activated graphite materials (AMGs) is systematically investigated. The material characterization results demonstrate the activation temperature imposes distinct influence on the morphology, interlayer distance (d
002
), crystalline size (L
c
), specific surface area and surface functional groups of the AMGs. At the optimized activation temperature of 550 °C, the activated graphite (AMG-55) presents enlarged d
002
of 0.3451 nm, small L
c
of 14.61 nm and lowest surface oxygen content (1.79%). Moreover, the moderate etching reactions of KOH at 550 °C results in the highest specific surface area (11.91 m
2
g
−1
) and the creation of abundant of nanosheets which construct rich mesopores for convenient K
+
diffusion. Benefitted from the high purity, increased activated sites for K
+
association as well as the accelerated charge transfer/ion diffusion kinetics, the AMG-55 electrode exhibits high reversible capacity (262.3 mAh g
−1
), superior cycling ability and best rate performance among the activated samples. A stable charge capacity of 171.9 mAh g
−1
still can be maintained after 200 discharge/charge cycles at 0.1 A g
−1
with a favorable capacity retention of 65.5%. Moreover, the electrode releases a high reversible capacity of 162.1 mAh g
−1
at the large current density of 0.6 A g
−1
, suggesting the promising application potential of activated graphite for high-performance KIBs.
Lead-doped TiO 2 nanofibers (TNFs) are fabricated by using an electrospun method, followed by the in situ preparation of perovskite-sensitized photoanode for use in perovskite solar cells (PSC). The ...electrospun TNFs can provide direct pathways for the rapid collection and transmission of photogenerated electrons. The photoanode based on the in situ method shows not only excellent contacting between the TNF and perovskite, but also abundant perovskite filling in it. These can be conducive not only to the separation and transmission of the electron and hole, but also to the absorption and utilization of sunlight. Finally, a high performance PSC with the cell efficiency of 9.03% is obtained without any hole transporting materials.
Solvothermal method is used to obtain N-doped graphene hydrogels (NGHs) using hydroxylamine hydrochloride or hydroxylamine (HA) as the chemical reductant and dopant. During the process, N-doping and ...reduction of graphene oxide have been achieved simultaneously. The products have been characterized by X-ray diffraction, X-ray photoelectron, Raman spectroscopy and electrochemistry. The results show that the electrical conductivity, microstructure and doping level of NGHs are influenced by the type and quantity of reductants, temperature and time of the reaction. Their capacitive behavior has been investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in an alkaline electrolyte using the two-electrode symmetric capacitor test. The NGHs prepared at 150 °C for 12 h using HA as reductant (NGH–HA12) has N-doping level of 4.32% in atom and exhibits a specific capacitance of 205 F g−1 and good cycling stability. The energy density and power density can reach to 3.65 W h kg−1 and 20.5 kW kg−1 at a discharge of 100 A g−1 for the symmetric capacitor assembled using NGH–HA12.
•N-doped graphene hydrogels (NGHs) were prepared by thermally treating graphene oxide.•The optimum conditions were determined by using hydroxylamine as reducing agent.•The capacitor assembled by the optimum NHGs exhibit good capacitive performance.
Zinc-ion batteries are considered as promising energy storage devices for large-scale energy storage due to the simple operation, low cost, and high safety, while their performances are determined by ...the cathode materials’ properties. Polypyrrole (PPy) can be used as the cathode material of zinc-ion battery, however, its poor cyclic stability limits the practical application. Considering the fact that electrolytes containing zinc ions are used in zinc ion batteries, the PPy cathode material has been electrodeposited on carbon cloth (CC) by using ZnSO
4
solution as electrolyte (PPy-ZS/CC). The results show that PPy/CC-ZS exhibits higher specific capacity and cyclic stability than the electrode prepared in NaH
2
PO
4
solution because the participation of ZnSO
4
in the deposition process makes PPy-ZS more suitable for the ZnSO
4
electrolyte of batteries. The specific capacity of the PPy-ZS has been increased by 24 mAh g
−1
compared with the capacity of PPy deposited in the NaH
2
PO
4
system; after the 1000-cycle test, the capacity retention is 80%. Furthermore, PPy-ZS’s specific capacity can reach 167 mAh g
−1
at 0.05A g
−1
when the battery is assembled in 2.0 mol L
−1
ZnSO
4
+ 70 mmol L
−1
NH
4
I electrolyte. After 2000 repeated charge/discharge tests at 4.5 A g
−1
, Zn//PPy-I-ZS still maintains 75% of the initial capacity, showing quite good stability. It provides an effective method to improve the performance of PPy-based cathode material in Zn-ion battery.
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