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Based on quantum chemical calculations, we predict strong solvatochromism in a light-driven molecular photocatalyst for hydrogen generation, i.e., we show that the electronic and optical properties of the photocatalyst strongly depend on the solvent it is dissolved in. Our calculations in particular indicate a solvent dependent relocation of the highest occupied molecular orbital (HOMO). Ground-state density functional theory and linear response time dependent density functional theory calculations are applied in order to investigate the influence of implicit solvents on the structural, electronic and optical properties of a molecular photocatalyst. Only at high dielectric constants of the solvent, the HOMO is located at the metal center of the photosensitizer, whereas at low dielectric constants the HOMO is centered at the metal atom of the catalytically active complex. We elucidate the electronic origins of this strong solvatochromic effect and sketch the consequences of these insights for the use of photocatalysts in different environments.

In this review, a discussion on renewable sources of energy with clear focus on solar cell applications is presented. Especially, possible future directions for development of dye-sensitized solar cells (DSSCs) are discussed. Dye-sensitized solar cells have become an important topic of research due to its high importance in energy conversion. Current DSSCs are based on either metal dye sensitizers, metal-free organic dyes or natural dyes. They have been extensively studied due to their low cost, simple preparation methodology, low toxicity, and ease of production. Still there is a need to find more abundant DSSC materials that at same time exhibit long-term stability. Computational studies have been an important ally for developing/designing new dye sensitizers. They are reviewed here with a special emphasis on the benefit of such studies. The conceptual understanding of development and working principle of photoactive DSSC materials are the primary feature of the review followed by examples of studies on different dye sensitizers using scarce to abundant metal based dyes and metal free organic dyes with donor-π-acceptor geometries for both n- and p-type DSSCs. The proper choice of organic dyes including donor, spacer, or acceptor is discussed and a prospective on dual donor based dyes is presented.

Nahdlatul Ulama merupakan organisasi islam terbesar di dunia. Menyambut abad ke-2 Organisasi Nahdlatul Ulama merupakan momentum penting dalam perjalanan organisasi. Transformasi digital dalam tubuh Nahdlatul Ulama sangat perlu dilakukan untuk memutar roda organisasi kedepan. Langkah awal dalam transformasi digital adalah proses digitalisasi dan pemahaman yang baik atas data tersebut.

Originally planned as an on-site meeting, the inaugural CataLight Young Scientist Symposium (CYSS) took place as a fully online conference in November 2020. Dedicated to various aspects of photocatalysis, namely synthesis, theory, characterization, and application, CYSS aimed to provide a stage for early-career scientists to connect to each other and present their research to peers in the field. While still keeping a traditional on-site conference format including both plenary and poster sessions, several minor and major changes had to be applied to the format to deliver a full experience. In this report, we highlight key steps in the organization of such an online conference, laying a focus on using mostly open source software to minimize costs, and discuss differences to both on-site and other online conference formats.

Conductive polymers represent a promising alternative to semiconducting oxide electrodes typically used in dye-sensitized cathodes as they more easily allow a tuning of the physicochemical properties. This can then also be very beneficial for using them in light-driven catalysis. In this computational study, we address the coupling of Ru-based photosensitizers to a polymer matrix by combining two different first-principles electronic structure approaches. We use a periodic density functional theory code to properly account for the delocalized nature of the electronic states in the polymer. These ground state investigations are complemented by time-dependent density functional theory simulations to assess the Franck-Condon photophysics of the present photoactive hybrid material based on a molecular model system. Our results are consistent with recent experimental observations and allow to elucidate the light-driven redox chemical processes -- eventually leading to charge separation -- in the present functional hybrid systems with potential application as photocathode materials.

In view of the wreath of potential functionalities two-dimensional (2D) transition-metal dichalcogenides can offer, we study here tuning pathways of 2D lateral arrangements of structures. Specifically, we have systematically doped a pristine 2D ${\mathrm{MoS}}_{2}$ with ${\mathrm{WS}}_{2}$ domains of varying sizes. The resulting materials made of ${\mathrm{MoS}}_{2}$ with ${\mathrm{WS}}_{2}$ have distinct structural, electronic, and optical properties, which we analyze in detail. By including spin-orbit coupling in our quantum mechanical calculations, we were able to resolve the band structure of these lateral structures. Our analysis reveals a decrease in the band gap from ${\mathrm{MoS}}_{2}$ and ${\mathrm{WS}}_{2}$ to ${\mathrm{MoS}}_{2}/{\mathrm{WS}}_{2}$. The results underline the nature and role of the ${d}_{{z}^{2}}$ and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ orbitals in the pristine and hybrid 2D structures, respectively, while indicating the possibility of a charge transfer from W to Mo atoms within the 2D hybrid structures. The dielectric matrix computed using the Bethe-Salpeter equation significantly affects the imaginary dielectric function and hence the absorption spectra of the lateral structures. In the end, we discuss the relevance of our work in paving a pathway for a selective tuning of the optoelectronic properties of 2D lateral heterostructures in view of optoelectronic applications.

Noble metals (Au and Ag) are the primary raw materials which have vast potential application ranging from across biosensor, biomedicine, science, and engineering fundamental. However, alloying them will enhance the efficiency and applicability of noble metals. Employing the linear-weight (LW) technique to construct a dielectric function of a binary solution is still disputed. However, this method is still widely used to examine Localized Surface Plasmon Resonance (LSPR) of Au-Ag binary solution. In this work, the calculation of electromagnetic response such as Localized Surface Plasmon Resonance (LSPR) of bimetallic Au-Ag nanorod was performed by means of MNPBEM package. We utilized nanorod-shaped with two different excitation modes, namely, Transverse Mode (TM) and Longitudinal Mode (LM), and various compositions to investigate their LSPR shifting anomalies. Moreover, we employed the LW technique to construct their dielectric function and analyze the LSPR anomalies. Interestingly, we found that using LW approximation, the resonance peak of TM is separate into two peaks. These peaks originated from the free electron of Au and Ag respectively, however, some of LSPRs peak did not occur amongst peak of pure Au and Ag. Practically, using LW method the resonance peak should be located amongst their individual elements. This work has provided the limitation of using silver fraction and the related aspect ratios to predict the LSPR spectra of Au and Ag on nanorod-shaped.

In this study, we have performed the incident electrical field angle effect in localized surface plasmon resonance (LSPR) spectra of bimetallic Ag–Au nanorod using Metallic Nano-Particle Boundary Element Method (MNPBEM) based on the boundary element method. The diameter and length of nanorod are 40 nm and 100 nm, respectively. The fraction of Ag in bimetallic Agx, Au(100-x) are 0, 20, 40, 60, 80, and 100 within weight percent. The dielectric function of Ag–Au was generated by linear approximation and the incident angle used from 0 to 90 degrees. We found that the intensity of the extinction curve shows decreasing follow logistic type curve as the incident angle increases whereas the resonance peak is constant. For a given silver fraction in bimetallic Ag-Au, the resonance peak of LSPR shifted to higher energy or blue-shift and the intensity increased. Interestingly, the LSPR of bimetallic Ag–Au occurred in the visible range and the transition mode from longitudinal to transverse mode was observed at the angle greater than 60 degrees.

We have studied the effect on localized surface plasmon resonance (LSPR) of Au-nanorod (AuNR) coated TiO2 (Au@TiO2) and SiO2 (Au@SiO2). The length and diameter of AuNR are 70 nm and 20 nm, respectively. For this purpose, then AuNR was coated by TiO2 and SiO2 with thickness varying from 2nm to 20nm with increment 2nm. The LSPR exhibited two modes, transverse mode (TM) and longitudinal mode (LM) as commonly was found in a rod-shaped particle. Interestingly, the peak of extinction red-shift as the thickness increased both TM and LM. Increasing volume and refractive index around AuNR contributed to red-shift, therefore the rate of decreasing energy TiO2 faster than SiO2. Furthermore, we have also observed the peak of LSPR extinction curve of Au@TiO2 have a similar trend to Au@SiO2 as the thickness increased, but its beginning to decrease at ∼8nm. In the LM, for a given thickness, we found the peak of extinction curve Au@TiO2 show more than one peak present around ∼2-3nm and ∼8nm. However, only one peak happened in Au@SiO2. In a sense, Au coated TiO2 can be fully utilized to enhance photocatalytic activity under visible light of AuNR and useful in photocatalytic activity, on the other hand, SiO2 plays an insignificant role for a certain limit thickness under visible light – near-infrared.

In this study, we have systematically investigated the sensitivity of surface plasmon resonance bimetallic silver-gold alloys by means of metallic nanoparticle simulation, MNPBEM with respect to the diameter, mole fraction, and refractive index medium variation. The sensitivity of surface plasmon resonance was obtained from a fitting linear between the value of the peak position LSPR spectra and the refractive index medium. Interestingly, it was found the sensitivity of surface plasmon resonance increased as the diameter increased for a diameter less than 40 nm, whereas the sensitivity of surface plasmon resonance exhibited the fluctuation values for diameter above 40 nm. The highest value of the sensitivity occurred at the silver mole fraction at x = 0.6 rather than at x = 1.0 (pure silver particle). This result also showed the sensitivity of surface plasmon resonance pure silver particle (x = 1) was greater than gold particle (x = 0). The sensitivity of surface plasmon resonance was not only affected by the diameter but also influenced by the mole fraction.