Z-Scheme BiVO/g-CN Photocatalyst-With or Without an Electron Mediator?

The hybrid system BiVO/g-CN is a prospective photocatalyst because of the favorable mutual alignment of the energy bands of both semiconductors. However, the path of the photocatalytic process is still unclear because of contradictory information in the literature on whether the mechanism of charge carrier separation at the BiVO/g-CN interface is band-to-band or Z-scheme. In this work, we clarified this issue by comparative photocatalytic studies with the use of systems without a mediator and with different kinds of mediators including Au nanoparticles, fullerene derivatives, and the Fe/Fe redox couple.

Comparative Studies of g-CN and CNS Organic Semiconductors-Synthesis, Properties, and Application in the Catalytic Oxygen Reduction.

Exfoliated g-CN is a well-known semiconductor utilized in heterogenous photocatalysis and water splitting. An improvement in light harvesting and separation of photogenerated charge carriers may be obtained by polymer doping with sulfur. In this work, we incorporate sulfur into the polymer chain by chemical polymerization of trithiocyanuric acid (CNSH) to obtain CNS.

Enhanced Performance of Camphorsulfonic Acid-Doped Perovskite Solar Cells.

High-quality perovskite film with large grains and therefore reduced grain boundaries plays a significant role in improving the power conversion efficiency (PCE) and ensuring good long-term stability of the perovskite solar cells. In this work, we found that adding camphorsulfonic acid (CSA), a Lewis base, to the perovskite solution results in the crystallization of larger perovskite grains. By varying the concentration of CSA, we found that the optimal concentration of the additive is 1 mg/mL, which leads to an 20% increase in PCE of the cells compared to the reference CSA-free cell.

Mono- and Di-Pyrene [60]Fullerene and [70]Fullerene Derivatives as Potential Components for Photovoltaic Devices.

In the present work, we report the successful synthesis and characterization of six (two new) fullerene mono- and di-pyrene derivatives based on C and C fullerenes. The synthesized compounds were characterized by spectral methods (ESI-MS, H-NMR, C-NMR, UV-Vis, FT-IR, photoluminescence and photocurrent spectroscopy). The energy of HOMO and LUMO levels and the band gaps were determined from cyclic voltammetry and compared with the theoretical values calculated according to the DFT/B3LYP/6-31G(d) and DFT/PBE/6-311G(d,p) approach for fully optimized molecular structures at the DFT/B3LYP/6-31G(d) level.

A comprehensive optical and electrical study of unsymmetrical imine with four thiophene rings and their binary and ternary compositions with PTB7 and PCBM towards organic photovoltaics.

A new unsymmetrical imine with four thiophene rings was synthesized in a one-step reaction, starting from the commercially available and relatively inexpensive reagents. The obtained imine in the form of thin films exhibited photoluminescence properties in the 1.8-2.

Mixed solutions of silver cation and chloride anion in acetonitrile: voltammetric and EQCM study.

Electrochemical behavior of Pt and Au electrodes in acetonitrile solutions at different concentration ratios of Cl(-) and Ag(+) ions was studied by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The composition of the mixed silver chloride solutions, i.e.

Electrodeposition of poly(N-vinylcarbazole) at the three-phase junction. Formation of very different polymer structures.

Poly(N-vinylcarbazole) films can be deposited at the three-phase boundary when the organic phase contains only monomer, N-vinylcarbazole, while the aqueous phase contains supporting electrolyte. A cylindrical platinum microelectrode is immersed into the two-liquid system in such a way that a part of it is located in one liquid and the other part resides in the second liquid. The thickness of the reaction layer, or the width of the microelectrode zone where the polymer grows, depends on the kind of ions present in the aqueous phase and the time of the experiment.

Time-temperature superposition for viscoelastic properties of regioregular poly(3-hexylthiophene) films.

Shear moduli were determined for chemically polymerized and solvent cast regioregular poly(3-hexylthiophene) films, using thickness shear mode acoustic wave resonators. The results are strikingly different to those for electropolymerized regiorandom poly(3-hexylthiophene) films. The time scale of the measurement was varied directly by use of higher harmonics of the acoustic wave resonator and indirectly via temperature.

Dynamics of regioregular conducting polymer electrodes in response to electrochemical stimuli.

We report thickness shear mode resonator acoustic wave data for films of regioregular poly(3-hexylthiophene) films exposed to acetonitrile solutions of LiClO4. Both the current- and acoustic wave-responses to constant (or slowly swept) potential show different regimes, whose characteristics, which are quite different to those of regiorandom electropolymerized films, can be interpreted in terms of crystalline and non-crystalline material. Oxidation of crystalline material, which occurs at low potentials, is dominated by anion transfer; as a result of the associated electrostatic effects, the film stiffens.