Novel MoWO4 with ZnO nanoflowers was synthesized on multi-walled carbon nanotubes (MW-Z@MWCNTs) through a simple hydrothermal method, and this unique structure was applied as a counter electrode (CE) for dye-sensitized solar cells (DSSC) for the first time. The synergetic effect of ZnO nanoflowers and MoWO4 on MWCNTs was systematically investigated by different techniques. The amount of MWCNTs was optimized to achieve the best DSSC performance. It was found that the 1.5% MW-Z@MWCNTs composite structure had the highest power conversion efficiency of 9.96%, which is greater than that of traditional Pt CE. Therefore, MW-Z@MWCNTs-based CE can be used to replace traditional Pt-based electrodes in the future.

This research was to study the preparation of fluorescent dust powder to enhance the detection of ultra-bright latent fingerprints using natural plant extract associated with adsorption on silica gel particles by a simple and cheap method environmentally friendly. To study the physical and chemical properties of the fluorescent powder, various factors affecting the latent fingerprints detection including different surface characteristics, temperature, time, and overlapping passive fingerprints were investigated. From the results, it was found that the fingerprints on the surface of different materials could be performed, and gave good inspection trace,which can be seen with naked eye and appear brightly under UV light at a wavelength of 366 nm. For the persistence study of the latent fingerprints, it was also found that when kept it in a dark place at room temperature for 30 days, the fingerprints were still visible to the naked eye and glow clearly under UV light.In addition, the overlapping fingerprints can be clearly identified. Therefore, the study of the fluorescent silica gel dust powder demonstrates good performance,and it is a potential use to detect latent fingerprints as a witness in forensic processes.

The electrode plays an important role in dye-sensitized solar cells (DSSCs). Preparation of the electrode should be simple and should result in high performance of its DSSC. We herein demonstrated high-performance and easily prepared Silver nanoparticles adhered on Reduced graphene oxide-Platinum composites (Ag-RGO/Pt) as counter electrodes (CEs) and TiO 2 on RGO sheets with Ag (TiO 2-RGO/Ag) as photoanode (PE) in DSSCs. The 1:2 Ag-RGO/Pt CE and 0.5% TiO 2-RGO/Ag PE showed an overall highest power conversion efficiency of 9.15% under (1.5 AM) solar irradiation. The optimal weight ratio of Ag:RGO:Pt materials was also examined. Moreover, we showed that incorporation of Ag nanoparticles into the counter electrode successfully improved interfacial charge transfer resulting in high electrocatalytic activity for the reduction of triiodide to iodide redox, which in turn could enhance the performance of the DSSCs.

To address the issues associated with traditional counter electrodes, a novel gamma-irradiated chitosan-doped reduced graphene-CuInS2 composite (Chi@RGO-CIS) was used as the counter electrode (CE).

요 약. 염료감을 태양전지(DSSC)는 대체에너지 집적제로서 낮은 생산단가로 고에너지 전환 효과를 볼 수 있다. 친환경 적이며 효과가 큰 무금속 염료감응제의 개발이 중요하다. 본 연구에서 유기 감광제로주제어: 유기염료 감응제, 집광 소재, 염료감응 태양전지 ABSTRACT. Dye-sensitized solar cell (DSSC); an alternate energy source harvester has gained some attractive features such as high-energy conversion efficiency low production cost. Dye-sensitizer is a basic component of DSSC, which affecting the performance of the energy conversion efficiency. Current research has been focusing on development of high efficiency, metal-free dye-sensitizers, which would be more environmental friendly. We had successfully explored synthetic route to 6,6'-(1,2,5-oxadiazole-3,4-diyl)dipyridine-2,4-dicarboxylic acid (3A) which has been used as organic sensitizer. Investigation of light conversion efficiency (η) of the compound uses standard measurement condition (one sun simulated irradiation, AM 1.5, 100 mW/cm 2 ) showed that it could reach 1.00% (JSC=2.63 mAcm -2 , VOC=0.64 V and FF=0.59). Under the same conditions, the ruthenium complex (N719) gave the conversion efficiency as high as 4.02%(JSC=10.50 mAcm -2 , VOC=0.67V and FF=0.57).

A novel tungsten disulfide-molybdenum copper oxide composite supported with graphene quantum dots (WM@GQDs) has been synthesized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs) using a simple and low-cost ultrasonication method. The unique structure of WM@GQDs exhibits excellent power conversion efficiency due to its high catalytic activity and charge transport properties. In addition, the graphene quantum dots (GQDs) provide more active sites in the zero-dimensional materials for an I/I3− redox reaction which can improve the electrical and optical properties of the composite. The results indicate that the amount of GQDs in the composite affect the effectiveness of solar devices. When 0.9%wt of GQDs was used, the WM@GQDs composite achieved an efficiency of 10.38%, which is higher than that of the expensive platinum CE under the same conditions. The mechanism behind the improved power conversion efficiency (PCE) of the composite sample is also discussed in detail. Therefore, WM@GQDs can be an efficient material to replace platinum in DSSCs as a CE.

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A large amount of agricultural waste was used to prepare cellulose (Cel) and then the surface was modified with PEI (Cel-PEI) using the microwave method. To be used as a metal adsorbent, the adsorption of Cr (VI) from an aqueous solution by Cel-PEI was measured using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques. The parameters of Cr (VI) adsorption in solution by the Cel-PEI adsorbent were as follows: the pH of the solution was 3, the concentration of the chromium solution was 100 mg/L, and the adsorption time was 180 min at 30 °C using 0.01 g of adsorbent. Cel-PEI had a Cr (VI) adsorption capacity of 106.60 mg/g, while the unadjusted Cel was 23.40 mg/g and the material recovery showed a decrease in efficiency of 22.19% and 54.27% in the second and third cycles, respectively. The absorption isotherm of chromium adsorption was also observed. The Cel-PEI material conformed to the Langmuir model with an R2 value of 0.9997. The kinetics of chromium adsorption showed that under pseudo-second-order analysis, with R2 values of 0.9909 and 0.9958 for Cel and Cel-PEI materials, respectively. The G° and H° values of the adsorption process were negative, indicating that the adsorption is spontaneous and that the adsorption process is exothermic. The efficient preparation adsorbent materials for Cr (VI) was achieved using a short microwave method that is low-cost and environmentally friendly for use in the treatment of Cr-contaminated wastewater.