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ZnO/NiO composite photoanodes for dye-sensitized solar cells (DSSCs) were synthesized by an all solid state mothed. The effect of as-prepared NiO with NiCl2·6H2O and Ni(NO3)2·6H2O precusor was investigated using X-ray diffraction (XRD), field-emission scaning electron microscope (FESEM), energy dispersive X-ray analysis (EDAX), UV–visible absorption spectra (UV–vis), electrochemical impedance spectroscopy (EIS), and open circuit voltage decay (OCVD) characterization techniques. NiO enhanced the performance of DSSCs because of the energy level potential difference between NiO and ZnO, which accelerated the electron transfer at the ZnO/dye/electrolyte interface. Using ZnO/NiO composite photoanodes attained the maximum power conversion efficiency (PCE) of 6.60% in DSSCs. Moreover, saturated Zn(Ac)2 ethanol solution-processed ZnO/NiO composite photoanodes showed excellent optical characteristic and prolonged carrier lifetime to contrast unprocessed ones. This post-processed photoanodes exhibited a short-circuit current density (JSC) of 22.34 mA cm−2 and a PCE of 7.01%, and these values were higher than those of the isolated ZnO/NiO photoanodes. These results pave the way to further improve the performance and potential application of DSSCs.

An interesting subject of non-fuel utilization of coal is the synthesis of high-performance coal-based carbon (CBC) materials to replace expensive Pt counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). Selection of coal source, treatment, and structural optimization of coal should be considered to obtain high-performance CBC CEs. In this study, a coal-based porous carbon material with low cost and high performance was synthesized from three kinds of pulverized coal (collected from different regions of Xinjiang, China) through chemical activation followed by acid washing oxidation treatment. The prepared porous CBC material exhibited higher catalytic activity for the reduction of I−/I3− than Pt. The use of carbon nanotubes (CNTs) plus prepared porous CBC/CNTs composite materials as CEs for DSSCs led to a VOC of 0.62 V, a JSC of 21.92 mA cm−2, an FF of 0.42, and a conversion efficiency of 5.75%, which is higher than those of CEs made of porous CBC, CNTs, or Pt. The improvement in the conversion efficiency could be attributed to the synergistic effect of the good catalytic activity of the prepared CBC materials and the good conductivity of CNTs. Moreover, the double-layer structure played an important role in improving the adhesion and electron transport capacity. Results provide a theoretical basis for the possible use of cheap CBCs as CEs for thin-film solar cells. We use the ZnO as photoanode; the dye is N719.

Charge recombination at the ZnO photoanode/electrolyte interface is one of the major limitations for high performance dye-sensitized solar cells (DSSCs) toward their theoretical power conversion efficiency (PCE). Here, we proposed an efficient approach for reducing this interfacial losses and consequently facilitating charge transfer by decorating a hydrophobic thin-film on the surface of the dye-coated zinc oxide photoanode via 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) hexane solution immersing. As a result, a high PCE of 8.22% was obtained, which far exceeded the efficiency of 5.40% in a conventional DSSC without PFDTES treatment. Furthermore, PFDTES treatment also largely elongated the lifetime of photogenerated electrons, and maintained a good photo-response at the photoelectrode. This work provides a comprehensive explanation of electron injection, transfer and recombination at the ZnO photoanode/electrolyte interface, and a promising strategy to explore high efficiency ZnO-based DSSCs.

Dye-sensitized solar cells (DSSCs) have many advantages, but the use of expensive platinum counter electrodes (CEs) limits their industrial applications. In this work, a Co–Ni/carbon aerogel composite with a unique three-dimensional network structure and high specific surface area was prepared through simple ion exchange and carbonization of low-cost sodium alginate supramolecular hydrogels. Using this metal/carbon aerogel composite as the CE (hereafter denoted as CAE) of ZnO-based DSSCs, a photoelectric conversion efficiency (PCE) of 5.08% was obtained. This value was 94.44% of the PCE obtained using Pt. Analysis of current–voltage curves, cyclic voltammograms, and electrochemical impedance spectra revealed that the fabricated CAE had higher catalytic activity than a Pt CE and comparable charge-transfer ability. The adhesion of the CAE onto FTO was also strong with carbon paste as an adhesive.

Cuprite Cu 2 O particles with different morphologies and very narrow band gap were synthesized through combining a hot water bath process with a post calcination process. The ZnO was prepared by using a simple solid-state method. When using the ZnO/Cu 2 O composite as the photoanode, the ZnO/Cu 2 O-based dye-sensitized solar cells (DSSCs) yielded a conversion efficiency of 6.94% at the optimized polyhedron Cu 2 O addition amounts of 0.25 wt%, which is improved by 23.93% compared with the performance of the pure ZnO-based DSSCs (5.60%). After introducing a ZnO buffer layer, the obtained bilayer ZnO/Cu 2 O-based DSSCs achieved a significantly elevated efficiency up to 7.02%, which corresponds to a 24.03% improvement compared with the pure bilayer-based one. This improvement can be attributed to the large specific surface area and pore structure of ZnO/Cu 2 O composite materials and the conductivity of Cu 2 O, which offsets the inherent shortages of ZnO of lower anchoring site density and poor conductivity, and generates some additional advantages, such as a lower charge transfer resistance, higher dye-loading quantity, longer electron lifetime, and reduced charge recombination.

As one of the world’s most active intracontinental mountain belts, Tien Shan has posed questions for researchers regarding the formation of different tectonic units and active shallow seismicity. Here, we used a huge data set comprising of 7094 earthquakes from local, regional and teleseismic seismic stations. We used waveform modeling and multi-scale double-difference earthquake relocation technique to better constrain the source parameters of the earthquakes. The new set of events provided us with better initial earthquake locations for further tomographic investigation. We found that reverse-faulting earthquakes dominate the whole study area while the fault plane solutions for earthquakes beneath the northwestern Tarim Basin and the Main Pamir Thrust are diverse. There is a low-velocity anomaly beneath Bashkaingdy at depth of 80 km, and high-velocity anomalies beneath central Tien Shan at shallower depths. These observations are the keys to understand the mechanism of Tien Shan’s formation because of Tarim Basin northward and Kazakh Shield’s southward subduction in the south and north respectively. Velocities beneath western Tien Shan are relatively high. We thus infer that the Western Tien Shan is relatively less deformed than the eastern Tien Shan primarily due to a relatively brittle mantle.

A comparative study of two methods for the synthesis of hierarchical structural CuBi2O4 particles was performed and the prepared samples were used in ZnO-based dye-sensitized solar cells (DSSCs) as an inorganic photosensitizer and additive for the ZnO anode. The structure, morphology, and light absorption were characterized by X-ray diffraction, scanning electron microscopy, and UV–Visible diffuse reflectance spectra. The photovoltaic performance was also investigated. Results indicate that this new type of thin-film solar cell, namely, ZnO/CuBi2O4/Pt (with CuBi2O4 instead of dye), yielded an overall light conversion efficiency of 0.45%. This result suggests that CuBi2O4 is highly likely to develop into a promising inorganic photosensitizer through further structural optimization and adjustment. By contrast, CuBi2O4 was also added into the ZnO to form a composite photoanode and sensitized by N719 dye thereafter. Results show that the addition of a minimal amount of CuBi2O4 (0.3 wt%) improves the photovoltaic efficiency by 25% compared with that of the pure ZnO-based DSSCs. The reason for such improvement was discussed with an interfacial charge transfer mechanism.

Quaternary chalcopyrite sulfide semiconductors Cu 2 XSnS 4 (X = Mn, Fe, Co, Ni, Zn and Cd) are successfully prepared by using a solvothermal method. Crystal structure, elemental composition and morphology of the as-synthesized nanoflowers are characterised using XRD, XPS, EDS, TEM and SEM. Photovoltaic and catalytic performances based on prepared samples as counter-electrode (CE) materials in ZnO-based dye-sensitised solar cells (DSSCs) are investigated based on N719 dye and iodide/triiodide electrolyte. Notably, Cu 2 XSnS 4 (X = Mn, Fe, Co, Ni, Zn, Cd) all show excellent catalytic activity for the reduction of I 3 − to I − in the electrolyte. In addition, Cu 2 MnSnS 4 and Cu 2 NiSnS 4 are explored as CE materials for DSSCs for the first time. Cu 2 MnSnS 4 and Cu 2 NiSnS 4 exhibit power conversion efficiency values of 6.18% and 6.12%, respectively, which are comparable to the photovoltaic performance of the DSSCs using a Pt CE (6.09%).

In this study, ZnO and ZnFe 2 O 4 nanostructures are rapidly synthesized at relatively low temperature and without any organic surfactants using an economical, simple, and environmentally friendly solid-state synthesis. Results shows that the formation of p–n heterojunction electric field at the interface between ZnFe 2 O 4 and ZnO is significantly effective in improving the open-circuit voltage ( V oc ) by efficiently promoting the separation efficiency of photogenerated electron–hole pairs on the surface of semiconductor, and an enhanced light-to-electric energy conversion efficiency of the dye-sensitized solar cell (DSSC) reaches 7.28%, which improve by 54.9% compared with that of pure ZnO based DSSCs (4.70%).

Using a pneumatic spray gun for a long-distance jet, we coated thioacetamide on the surface of ZnO. Thus, the adsorption capacity of N719 dyes greatly increased. The as-samples were characterised by linear sweep voltammetry and electrochemical impedance spectroscopy analysis. Results showed that the charge recombination resistance increased, which lowered the interface electron recombination rate between ZnO and the electrolyte and between the electrolyte and the dye. Finally, a photoelectric conversion efficiency of 8.28 ± 0.24% for ZnO-based dye-sensitized solar cells was achieved.