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In this present work, the synthesis of g-C 3 N 4 /TiO 2 nanocomposites with different wt.% g-C 3 N 4 to form a type-II heterostructure and its potential application towards photoelectrocatalytic water splitting was discussed. The synthesized g-C 3 N 4 nanoplatelets incorporated TiO 2 nanocomposites were characterized by various analytical techniques such as UV-vis diffuse reflectance spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and high-resolution transmission electron microscopy (HRTEM). HRTEM confirms the formation of type-II heterostructure consists of g-C 3 N 4 nanoplatelets incorporated titania in the nanocomposite. The photoelectrocatalytic activity of the TiO 2 , g-C 3 N 4 , and g-C 3 N 4 /TiO 2 nanocomposite were investigated under AM 1.5G (100 mW cm −2) illumination in 1 M KOH. The g-C 3 N 4 /TiO 2 (with 10 wt.% of g-C 3 N 4) nanocomposite photoanode exhibits photocurrent density of 142.7 μA cm −2 (at 1.23 V vs. RHE) which is ~ 1.8-fold higher than bare TiO 2 (80.5 μA cm −2 at 1.23 V vs. RHE). The enhancement in PEC activity explained by formation of type-II heterostructure between g-C 3 N 4 and TiO 2 , which reduced the recombination rate of photo-generated electron-hole pairs and also extends the absorption of TiO 2 to visible light range and boost up the interfacial charge transfer between electrode/electrolyte interface, which enhance the PEC activity of the g-C 3 N 4 /TiO 2 nanocomposite towards water splitting.

Trifunctional thiospinel-like M–NixSn2xS4x nanocomposite was synthesized with ease.

Owing to increase in energy demands and depletion in fossil fuels, solar energy conversion is the reliable and sustainable one for future. Among the solar energy conversion techniques, dye-sensitized solar cells (DSSC) have received much attention due to their ease of fabrication, cost-effectiveness, reliable and high proficiency in converting solar energy. The commercialization of DSSC is still hindered by usage of expensive materials like platinum counter electrodes. Therefore, researchers are focusing on developing low-cost and earth abundant alternatives. The present work involves hydrothermal synthesis of molybdenum trioxide (MoO 3) at various temperature ranges such as 400, 500, 600 and 700 °C and several other characterizations through various analytical techniques. On increasing the temperature range, the MoO 3 forms nanorod like structure. The synthesized materials are employed as counter electrode in DSSC, showed enhanced power conversion efficiency (PCE) on increasing the calcination temperature range. The maximum PCE of 4.13% is obtained for MoO 3 calcined at 600 °C, which is highly comparable with the high cost platinum CE based DSSC.

The quality of human life in the modern era seems to be highly reliable on the technology advancements and energy consumption. [1] Globally, around 85% of the energy depends on nonrenewable sources which may extinct within next few years. [2] In this context, solar cells in specifically dye-sensitized solar cells (DSSCs), which come under thin-filmbased third-generation solar cells, are considered to play a vital role of fulfilling the future energy needs by means of its proficient energy conversion potential, in addition to its lightweight, low-cost, reliable efficiency, multicolor options, and feasible for both indoor and outdoor applications. It is one of the most promising energy conversion devices from its technological discovery of early 1990s by Brain O'Regan and Michael Gratzel [3,4] In general, the working of DSSC depends on five major components, namely, 1) substrate, 2) semiconductor nanolayer, 3) the sensitizer, 3) redox electrolyte, and 5) counter electrode. The schematic representation of a typical DSSC with components is shown in Figure 1.Initially, the photosensitizer (dye) of the DSSC usually in its ground state and the illumination of light over the DSSC excite the ground state dye molecules from highest occupied molecular orbital (HOMO) level to the lowest unoccupied molecular orbital (LUMO) level (1), and then the electron from the LUMO level jumps over the conduction band of the semiconductor in 150 ps (2) and reaches the TCO. The holes produced during the excitation of dye molecules are scavenged by the electrons from the redox electrolyte (4) in 0.5 μs. The electrons reached the TCO then move to the cathode through the external circuit and power up the electrical load. Finally, the oxidized electrolyte gets reduced at the cathode (5) in 10 μs. [5,6] Besides these carrier-transport processes, some adverse reactions like nonradiative carrier-recombination paths will occur that desperately reduces the overall device performance. [7] Such unfavorable reactions are follows: nonradiative decay of immediate excitation of dye molecule to its ground state occurs in ns (6), plausible recombination of the electrons from the conduction band of the semiconductor material to the ground state of dye molecule occurs in ms (7), and to the electrolyte occurs in 100 ns to 1 ms (8), respectively. [8] The substrate for the photoanode and cathode is the most important component. Apart from this metal foil or polymeric film, transparent conductive oxide (TCO)-coated transparent glass substrate, such as fluorine-doped tin dioxide (FTO) or

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