Photocatalytic activity of CuInS2 nanoparticles synthesized via a simple and rapid microwave heating process

In this research, visible–light photocatalytic activities of CuInS2 nanoparticles for degradation of three organic dyes (rhodamine B; RhB, methylene blue; MB, and methyl orange; MO) were investigated. The CuInS2 nanoparticles were synthesized by a simple and rapid microwave heating process using sodium sulfide as a sulfur source and then characterized by x–ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), and UV–vis diffuse reflectance spectroscopy (UV–vis DRS) techniques. The synthesized CuInS2 nanoparticles exhibited excellent photocatalytic degradation activity to the cationic dyes (RhB and MB) when compared with that of anionic dye (MO). Zeta potential of the CuInS2 photocatalyst was measured to elucidate the adsorption ability toward dye molecules. A possible photocatalytic degradation mechanism was proposed based on active species quenching experiments and Mott–Schottky analysis

Surface Enhanced Raman Scattering in Graphene Quantum Dots Grown via Electrochemical Process

Graphene Quantum dots (GQDs) are used as a surface-enhanced Raman substrate for detecting target molecules with large specific surface areas and more accessible edges to enhance the signal of target molecules. The electrochemical process is used to synthesize GQDs in the solution-based process from which the SERS signals were obtained from GQDs Raman spectra. In this work, GQDs were grown via the electrochemical process with citric acid and potassium chloride (KCl) electrolyte solution to obtain GQDs in a colloidal solution-based format. Then, GQDs were characterized by transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy, respectively. From the results, SERS signals had observed via GQDs spectra through the Raman spectra at D (1326 cm−1) and G (1584 cm−1), in which D intensity is defined as the presence of defects on GQDs and G is the sp2 orbital of carbon signal. The increasing concentration of KCl in the electrolyte solution for 0.15M to 0.60M demonstrated the increment of Raman intensity at the D peak of GQDs up to 100 over the D peak of graphite. This result reveals the potential feasibility of GQDs as SERS applications compared to graphite signals

A Multi-Electron Transporting Layer for Efficient Perovskite Solar Cells

In this work, a multi-electron transporting layer (ETL) for efficient perovskite solar cells is investigated. The multi-ETL consists of five conditions including SnO2, SnO2/SnOx, TiO2, TiO2/SnO2, and TiO2/SnO2/SnOx. The best performance of PSC devices is found in the SnO2/SnOx double-layer and exhibits a power conversion efficiency equal to 18.39% higher than the device with a TiO2 single-layer of 14.57%. This enhancement in efficiency can be attributed to a decrease in charge transport resistance (Rct) and an increase in charge recombination resistance (Rrec). In addition, Rct and Rrec can be used to explain the comparable power conversion efficiency (PCE) between a PSC with a SnO2/SnOx double-layer and a PSC with a triple-layer, which is due to the compensation effect of Rct and Rrec parameters. Therefore, Rct and Rrec are good parameters to explain the efficiency enhancement in PSC. Thus, the Rct and Rrec from the electrochemical impedance spectroscopy (EIS) technique is an easy and alternative way to obtain information to understand and characterize the multi-ETL on PSC

Lanthanide Coordination Polymers of Mixed Phthalate/Adipate for Ratiometric Temperature Sensing in the Upper-Intermediate Temperature Range

Based on the mixed phthalate (phth^2–) and adipate (ad^2–), [Nd₂(ad)­(phth)₂(H₂O)₄] (<b>I</b>) and [Ln­(ad)_0.5(phth)­(H₂O)₂] (Ln = Eu^III (<b>II</b>), Gd^III (<b>III</b>), Tb^III (<b>IV</b>), Dy^III (<b>V</b>), Er^III (<b>VI</b>), Tm^III (<b>VII</b>), 1Eu^III:10Tb^III (<b>VIII</b>), 3Eu^III:10Tb^III (<b>IX</b>), and 5Eu^III:10Tb^III (<b>X</b>)) were synthesized and characterized. Complexes <b>VIII</b>–<b>X</b> show excellent ratiometric temperature sensing behavior in physiological and higher temperature ranges (303–423 K) rendered by the Tb^III-to-Eu^III energy transfer process. The efficiency of the process as illustrated through the lifetime measurements depends on both the Eu^III:Tb^III mole ratio and the temperature. The performance of <b>X</b> in terms of relative sensitivity (<i>S</i>_r), temperature resolution, and measurement repeatability were determined, revealing the maximum <i>S</i>_r (<i>S</i>_m) of 1.21%·K^–1 at 303 K with reliable temperature resolution and excellent repeatability

Efficient and Stable Carbon-Based Perovskite Solar Cells Enabled by Mixed CuPc:CuSCN Hole Transporting Layer for Indoor Applications

Perovskite solar cells (PSCs) are an innovative technology with great potential to offer cost-effective and high-performance devices for converting light into electricity that can be used for both outdoor and indoor applications. In this study, a novel hole-transporting layer (HTL) was created by mixing copper phthalocyanine (CuPc) molecules into a copper(I) thiocyanate (CuSCN) film and was applied to carbon-based PSCs with cesium/formamidinium (Cs0.17FA0.83Pb(I0.83Br0.17)3) as a photoabsorber. At the optimum concentration, a high power conversion efficiency (PCE) of 15.01% was achieved under AM1.5G test conditions, and 32.1% PCE was acquired under low-light 1000 lux conditions. It was discovered that the mixed CuPc:CuSCN HTL helps reduce trap density and improve the perovskite/HTL interface as well as the HTL/carbon interface. Moreover, the PSCs based on the mixed CuPc:CuSCN HTL provided better stability over 1 year due to the hydrophobicity of CuPc material. In addition, thermal stability was tested at 85 °C and the devices achieved an average efficiency drop of approximately 50% of the initial PCE value after 1000 h. UV light stability was also examined, and the results revealed that the average efficiency drop of 40% of the initial value for 70 min of exposure was observed. The work presented here represents an important step toward the practical implementation of the PSC as it paves the way for the development of cost-effective, stable, yet high-performance PSCs for both outdoor and indoor applications