The scarcity of inexpensive and efficient electrocatalyst for acid water oxidation to molecular oxygen presents the development of nonprecious catalysts for water oxidation a scientific priority. For water splitting, transition‐metal dichalcogenides have attracted great interest as advanced catalysts for hydrogen evolution reaction, but there has been no sincere attention to generate significant anodic current density of oxygen evolution reaction (OER) with these materials. Addressing this unmet need, here, the outstanding catalytic performance of MoS2 and TaS2 in OER is demonstrated. Chemically exfoliated 2D thin sheets of MoS2 and TaS2, in both of their 1T and 2H polymorph, have been employed for OER catalysis in acid medium. The best performance for oxygen evolution, which is also comparable to benchmark IrO2, comes out from 1T‐MoS2 followed by 1T‐TaS2, 2H‐MoS2, and 2H‐TaS2. Theoretical study reveals that the dominant catalytic activity is on edge sites instead of surface and corroborates the experimental results of polymorphic dependence of electrocatalytic activity. The materials have also shown moderate durability in the harsh acidic medium. The study brings up new set of electrocatalyst for oxygen evolution in acid regime that hitherto has remained largely unrevealed.

Although a lot of work has been reported on the growth and properties of 2D atomic layered materials, the growth mechanism for these crystals via the chemical vapor deposition method (CVD) has remained elusive. Here, a screw dislocation–driven spiral growth of SnSe2 crystal flakes via CVD is reported. The polymorph of as‐synthesized SnSe2 crystals is verified as 1T‐phase by both experimental characterization and theoretical calculation. The density functional theory study reveals morphology transformation during the growth process while phase‐field modeling unravels the screw dislocation propagation to form the pyramid‐like structure of SnSe2. The optical band gap of SnSe2 crystals relates to an indirect band gap of 1.0 eV. The photodetector devices based on SnSe2 crystals exhibit high responsivity and ultrafast response time in the microsecond regime.

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Meticulous surface engineering of layered structures toward new functionalities is a demanding challenge to the scientific community.Here, we introduce defects on varied MoS 2 surfaces by suitable doping of nitrogen atoms in a sulfur-rich reaction environment, resulting in stable and scalable phase conversion. The experimental characterizations along with the theoretical calculations within the framework of density functional theory establish the impact of nitrogen doping on stabilization of defects and reconstruction of the 2H to 1T phase. The as-synthesized MoS 2 samples exhibit excellent dye removal capacity in the dark, facilitated by a synergistic effect of reactive oxygen species (ROS) generation and adsorption. Positron annihilation spectroscopy and electron paramagnetic resonance studies substantiate the role of defects and associated sulfur vacancies toward ROS generation in the dark. Further, on the basis of its ample ROS generation in the dark and in the light, the commendable antimicrobial activity of the prepared MoS 2 samples against fungal pathogen Alternaria alternata has been demonstrated. Thus, the present study opens up a futuristic avenue to develop newer functional materials through defect engineering by suitable dopants toward superior performances in environment issues.