In Situ Simultaneous Growth of Layered SnSe2 and SnSe: a Linear Precursor Approach Manab Mandal, Prahalad K. Barman, Sagar Chowdhury, D. Manikandan, Nilanjan Basu, et al. Advanced Materials Interfaces, 2025 The synthesis of layered tin diselenide (SnSe2) and tin selenide (SnSe) can be achieved independently through distinct nucleation pathways using chemical vapor deposition (CVD). This study successfully achieves the simultaneous growth of SnSe₂ and SnSe, two structurally and functionally distinct tin selenide phases, through hot‐wall CVD. For the first time, this is accomplished through an innovative yet facile synthesis method involving a linear arrangement of precursor granules, which effectively overcame the typical limitations of synthesizing SnSe2 and SnSe from Se powder and SnI₂ granules. The dual‐phase growth is realized through precise control of precursor gradients, substrate temperature, and growth duration, with selenium stoichiometry and thermodynamic stability criteria dictated phase formation. A transport model is proposed to describe precursor concentration distribution and reaction rates, elucidating shape evolution and the combined growth of SnSe2 and SnSe. This study enhances the understanding of competitive growth dynamics and highlights the potential for multifunctional lateral heterostructures and phase‐engineered materials for optoelectronic and thermoelectric applications.
Massively Improved Water Desalination Performance Using Phase-Engineered MoS2 Nanopores D. Manikandan, Suman Chakraborty Nano Letters, 2025 Water scarcity affects billions globally, particularly in regions with limited freshwater resources, making the development of scalable and energy-efficient desalination technologies imperative. Advances in nanotechnology have led to the emergence of 2D nanoporous membranes, offering a promising route toward sustainable water purification. Here, using molecular dynamics simulations, we demonstrate that phase-engineered molybdenum disulfide (MoS2) membranes (1T and 1T' phases) significantly outperform their conventional 2H phase configuration in water desalination. These engineered structures exhibit an extraordinary ∼150% increase in water flux while maintaining exceptional ion rejection rates above 99%, surpassing the performance of other two-dimensional (2D) materials. This enhancement is attributed to the material's preferential phases, where the metallic nature and improved charge screening enhance water affinity, while structural distortions create smoother energy landscapes that enable faster water transport. These inferences establish the phase-engineered MoS2 membranes as a disruptive alternative to conventional reverse osmosis membranes, advancing the next-generation, energy-efficient desalination technologies.
Salinity gradient induced blue energy generation using two-dimensional membranes D. Manikandan, S. Karishma, Mukesh Kumar, Pramoda K. Nayak Npj 2d Materials and Applications, 2024 Salinity gradient energy (SGE), known as blue energy is harvested from mixing seawater with river water in a controlled way using ion exchange membranes (IEMs). Using 2D materials as IEMs improves the output power density from a few Wm−2 to a few thousands of Wm−2 over conventional membranes. In this review, we survey the efforts taken to employ the different 2D materials as nanoporous or lamellar membranes for SGE and provide a comprehensive analysis of the fundamental principles behind the SGE. Overall, this review is anticipated to explain how the 2D materials can make SGE a viable source of energy.
Strain relaxation in monolayer MoS2 over flexible substrate Nilanjan Basu, Ravindra Kumar, D. Manikandan, Madhura Ghosh Dastidar, Praveen Hedge, et al. Rsc Advances, 2023 Strain relaxation in 1L MoS2 transpires through crack formation at around 4.5% of strain.
Laser-Assisted Scalable Pore Fabrication in Graphene Membranes for Blue-Energy Generation Sharad Kumar Yadav, Manikandan D, Chob Singh, Mukesh Kumar, Aswathy G, et al. Chemphyschem, 2023 The osmotic energy from a salinity gradient (i. e. blue energy) is identified as a promising non‐intermittent renewable energy source for a sustainable technology. However, this membrane‐based technology is facing major limitations for large‐scale viability, primarily due to the poor membrane performance. An atomically thin 2D nanoporous material with high surface charge density resolves the bottleneck and leads to a new class of membrane material the salinity gradient energy. Although 2D nanoporous membranes show extremely high performance in terms of energy generation through the single pore, the fabrication and technical challenges such as ion concentration polarization make the nanoporous membrane a non‐viable solution. On the other hand, the mesoporous and micro porous structures in the 2D membrane result in improved energy generation with very low fabrication complexity. In the present work, we report femtosecond (fs) laser‐assisted scalable fabrication of μm to mm size pores on Graphene membrane for blue energy generation for the first time. A remarkable osmotic power in the order of μW has been achieved using mm size pores, which is about six orders of magnitudes higher compared to nanoporous membranes, which is mainly due to the diffusion‐osmosis driven large ionic flux. Our work paves the way towards fs laser‐assisted scalable pore creation in the 2D membrane for large‐scale osmotic power generation.
Pulsed Carrier Gas Assisted High-Quality Synthetic 3 R-Phase Sword-like MoS2: A Versatile Optoelectronic Material Ramesh Rajarapu, Prahalad Kanti Barman, Renu Yadav, Rabindra Biswas, Manikandan Devaraj, et al. ACS Nano, 2022 Synthesizing a material with the desired polymorphic phase in a chemical vapor deposition (CVD) process requires a delicate balance among various thermodynamic variables. Here, we present a methodology to synthesize rhombohedral (3R)-phase MoS2 in a well-defined sword-like geometry having lengths up to 120 μm, uniform width of 2-3 μm and thickness of 3-7 nm by controlling the carrier gas flow dynamics from continuous mode to pulsed mode during the CVD growth process. Characteristic signatures such as high degree of circular dichroism (∼58% at 100 K), distinct evolution of low-frequency Raman peaks and increasing intensity of second harmonic signals with increasing number of layers conclusively establish the 3R-phase of the material. A high value (∼844 pm/V) of second-order susceptibility for few-layer-thick MoS2 swords signifies the potential of MoS2 to serve as an atomically thin nonlinear medium. A field effect mobility of 40 cm2/V-s and Ion/Ioff ratio of ∼106 further confirm the electronic-grade standard of this 3R-phase MoS2. These findings are significant for the development of emerging quantum electronic devices utilizing valley-based physics and nonlinear optical phenomena in layered materials.
