ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
The new nanoporous framework [Gd4(di-nitro-BPDC)4(NO2)3(OH)(H2O)5]·(solvent) (I; di-nitro-BPDC2- = 2,2'-dinitrobiphenyl-4,4'-dicarboxylate) has been designed and synthesized through a simple one-pot reaction. In addition to its exceptional thermal and water stabilities, I exhibited multifunctional properties. A sudden CO2 uptake to a maximum of 4.51 mmol g-1 (195 K and 1 bar) with notable selectivity over O2 and N2 (CO2/O2 = 39 at 195 K and 0.10 bar, CO2/N2 = 46 at 195 K and 0.10 bar) and an isosteric adsorption enthalpy of 20.7(4) kJ mol-1 have been revealed. Depending on the temperature and humidity, I also showed distinguished superprotonic conductivities with a maximum value and activation energy of 6.17 × 10-2 S cm-1 (55 °C, 99 RH%, and 1 V AC voltage) and 0.43 eV, respectively. With respect to the linear dependence of conductivities on both temperature (25-55 °C at 99 RH%) and humidity (55-99 RH% at 25 °C), the potential of I in temperature and humidity sensing was evaluated, disclosing an excellent sensing resolution and exceptional accuracy, precision, and repeatability for the measurements.
ABSTRACT
A compact low-temperature plasma jet device was developed to use ambient air as plasma gas. The device was driven by a 2.52-kV high-voltage direct-current pulse in a burst mode, with a repetition rate of 2 kHz. The maximum plasma discharge current was 3.5 A, with an approximately 10 ns full-width half-maximum. Nitric oxide, hydroxyl radical, atomic oxygen, ozone, and hydrogen peroxide-important reactive oxygen and nitrogen species (RONS)-were mainly produced. The amount of plasma-generated RONS can be controlled by varying the pulse-modulation factors. After optimization, the plasma plume length was approximately 5 mm and the treatment temperature was less than 40 °C. The preliminary bactericidal effects were tested on Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant S. aureus (MRSA), and their biofilms. The results showed that the plasma can effectively inactivate S. aureus, P. aeruginosa, and MRSA in both time- and pulse-dependent manner. Thus, this produced plasma device proved to be an efficient tool for inactivating deteriorating bacteria. Further versatile utilization of this portable plasma generator is also promising.
ABSTRACT
Based on the mixed phthalate (phth2-) and adipate (ad2-), [Nd2(ad)(phth)2(H2O)4] (I) and [Ln(ad)0.5(phth)(H2O)2] (Ln = EuIII (II), GdIII (III), TbIII (IV), DyIII (V), ErIII (VI), TmIII (VII), 1EuIII:10TbIII (VIII), 3EuIII:10TbIII (IX), and 5EuIII:10TbIII (X)) were synthesized and characterized. Complexes VIII-X show excellent ratiometric temperature sensing behavior in physiological and higher temperature ranges (303-423 K) rendered by the TbIII-to-EuIII energy transfer process. The efficiency of the process as illustrated through the lifetime measurements depends on both the EuIII:TbIII mole ratio and the temperature. The performance of X in terms of relative sensitivity ( Sr), temperature resolution, and measurement repeatability were determined, revealing the maximum Sr ( Sm) of 1.21%·K-1 at 303 K with reliable temperature resolution and excellent repeatability.
