Designing of an efficient heterostructure photocatalyst for photocatalytic organic pollutant removal and H 2 production has been a subject of rigorous research intended to solve the related environmental aggravation and enormous energy crises. Z-scheme-based charge-transfer dynamics in a p−n heterostructure could significantly replicate the inherent power of natural photosynthesis, which is the key point to affect the transportation of photoinduced exciton pairs. In this finding, a series of p-type MoS 2 loaded with n-type NiFe-layered double hydroxide (LDH) forming a heterostructure MoS 2 /NiFe LDH were designed by electrostatic selfassembled chemistry and an in situ hydrothermal strategy for photocatalytic rhodamine B (RhB) dye degradation and H 2 production. The creation of p−n heterojunctions of type-II and Z-scheme mode of charge transfer modified the optical and electronic property of the as-synthesized MSLDH3, thereafter promoting the generation, separation, and migration of photoinduced electron−hole pairs. The as-synthesized MSLDH3 showed superior photocatalytic activities in degradation of RhB with H 2 evolution, which was enhanced by 3-and 4.5-fold and 10.9 and 19.2 times higher than that of NiFe LDH and MoS 2 , respectively. Last but not the least, heterostructure MSLDH3 possesses practical stability for its resultant enhanced photocatalytic activity with recyclability for everyday life.

Hydrogen evolution from water splitting by means of a photocatalytic approach is an ideal future energy source and free of fossil reserves, in contrary photocatalytic O 2 evolution remains a bottleneck due to high over potential and low efficiency. For reasonable use of solar light, photocatalysts must be sufficiently stable and efficient toward harvesting of sunlight from both theoretical and practical viewpoints. In this regard, here we have prepared MoS 2 -modified UiO-66-NH 2 MOF through a facile hydrothermal technique and evaluated its efficiency toward photocatalytic H 2 and O 2 evolution by water splitting in the presence of sacrificial agents. A couple of similar type of analyses have been studied previously; however, this analysis represents a diverse scientific approach on the basis of interfacial contact toward reveal the actual potential of nanoflakes MoS 2 as well as UiO-66-NH 2 . In this regard the as-synthesized photocatalyst was wellcharacterized by XRD, FTIR, UV−vis diffuse reflectance spectra, FESEM, HRTEM, XPS, and BET analysis techniques, which provide sufficient evidence toward successful synthesis of the pristine materials and efficacious anchorage of MoS 2 on the active surface of UiO-66-NH 2 by the ionic interaction between Zr−O and S/Mo. Among the synthesized photocatalysts (3 wt %) MoS 2 / UiO-66-NH 2 shows the optimum outcome toward H 2 and O 2 evolution, i.e., 512.9 μmol/h (4.37 times greater than bare UiO-66-NH 2 ) and 263.6 μmol/h (4.25 and 11.32 times greater than bare UiO-66-NH 2 and MoS 2 , respectively). The superior performance obtained by the composite is due to the synergistic effect of pristine UiO-66-NH 2 and MoS 2 which proceeds through a type-II interband alignment for the facile channelization of excitons. This investigation will bestow a beneficial blue-print to construct challenging photocatalysts and to find out the paramount performance toward photocatalytic water redox reaction.

Due to the enormous demand for effective conversion of solar energy and large-scale hydrogen production, cost-effective and long-lasting photocatalysts are believed to be necessary for global production of sustainable and clean hydrogen fuel. Robust and highly efficient p-n heterojunction photocatalysts have a striking ability to enhance light-harvesting capacity and retard the recombination of photoexcitons. A series of p-MoS/n-CaInS heterojunction composites with different MoS contents have been synthesized via a facile two-step hydrothermal technique in which rose-like p-MoS nanoflowers are decorated upon n-type cubic CIS microflowers. In the synthesis protocol highly dispersed MoS nanoflowers provided more active edge sites for the growth of c-CIS nuclei, leading to a hierarchical architecture with intimate interfacial contact. The formation of a hierarchical flower-like morphology of the photocatalyst has been established by an HRTEM and FESEM study. Electrochemical characterization, especially the slope of the curve from Mott-Schottky analysis and nature of the current from LSV, reveals the p-n heterojunction nature of the composite photocatalyst. The fabricated heterojunction photocatalysts were further examined for visible light photocatalytic H evolution. Far exceeding those for the neat c-CIS and MoS, it is seen that the p-MoS/n-CIS heterojunction photocatalyst with an optimum content of MoS exhibited enhanced H evolution using a 0.025 M NaS/NaSO solution as hole quenching agent under visible light illumination. The 0.5 wt % p-MoS/n-CIS photocatalyst presents a higher H production rate of 602.35 μmol h with 0.743 mA cm photocurrent density, 19 times and 8 times higher than those of neat c-CIS, respectively. This superior photocatalyic activity is due to the efficient separation of electron-hole charge carriers at the interface, as supported by a photoluminescence study and EIS measurements.

Nowadays the major research objective is to find an efficient renewable energy source which can be a potential solution to all our ongoing problems. With this regard, the interest has been blossoming toward effective photocatalytic HER and NRR at ambient condition. For the optimization of photocatalytic H2 evolution and NH3 production it is an exigent task to design a suitable photocatalytic semiconductor that hinders the low electron–hole separation efficiency. Benefiting from the combination of a 2D-2D semiconductor, we have proposed for the first time a series of p-MoS2/n-MgIn2S4 marigold flower-like heterojunction composites, with an excellent morphological contact interface through a facile two step hydrothermal process. The smart 2D-2D heterojunction structure provides large contact surface sites which reduce the migration distance between the separation sites of the photogenerated charge carrier to the heterojunction interface. This electron-rich system provided the multielectron pathway for the efficient reduction of nitrogen and can avoid the formation of high-energy intermediates. Thus, the high photocatalytic performance can be attributed to the heterojunction formation between two nanosheet, abundant exposed active sites via S–S linkage on the edge of metal sulfides and effective excitons separation. The developed MoS2/MIS heterojunction photocatalysts attain a high rate of NH3 production which is nearly 4 and 7 times higher than the bare MoS2 and MIS, and the rate of H2 evolution is 4 times higher than the bare MIS. The current investigation provides an excellent strategy to promote photocatalytic HER and NRR and sheds some light toward the development of efficient 2D based bifunctional materials.

Herein, a novel Cu-MoO3/g-C3N4 hybrid nanocomposite was successfully synthesized by a two-step strategy of one-pot pyrolysis followed by the impregnation method. The structure, phase, morphology and electronic environment of MoO3, g-C3N4 and Cu in the composite were determined by various characterization methods. The oxygen vacancies of MoO3 were ascertained by UV-DRS, Raman, and XPS analysis. The formation of the heterostructure was characterised by electrochemical measurements. The photocatalytic performance of the composite was investigated by the water reduction reaction and the reduction of an important inorganic pollutant, Cr(vi). In the presence of Cu NPs, the H2 evolution of the MoO3/g-C3N4 hybrid was found to be 652 μmol h-1 with an apparent energy conversion efficiency of 13.46%, and up to 95% of Cr(vi) was reduced using citric acid as a hole scavenger. The remarkably enhanced photocatalytic performance was attributed to the combined effect of the double Z-scheme mechanism and defective MoO3. The in situ formation process of the MoO3/g-C3N4 hybrid followed a direct Z-scheme charge transfer by generating a great number of defects at the solid-solid interface, similar to that of a conductor, and offered low electrical resistance, whereas loading of Cu NPs built up an indirect Z-scheme charge transfer to establish the double Z-scheme charge transfer mechanism. This hybrid material produces a photocurrent density of 12.1 mA cm-2, in good agreement with the photocatalytic activity. This study highlights the facilitation effect of MoO3 due to oxygen vacancies and charge transfer through the double Z-scheme mechanism to open up a new window in the field of 2D nanostructured photocatalytic materials.