2D materials have rapidly gained attention due to their exceptional properties like high surface area, flexibility, and tunable electronic characteristics. These attributes make them highly versatile for applications in energy storage, electronics, and biomedicine. Inspired by graphene's success, researchers are exploring other 2D materials from bulk crystals. Electrochemical exfoliation (ECE) is an efficient method for producing these materials, offering more sustainable mild conditions, quick processing, simple equipment, and high yields. While substantial progress has been made in the ECE of layered van der Waals (L-vdW) crystals, the exploration of layered non-van der Waals (L-NvdW) materials remains in its early stages. This review delves into using ECE to create 2D nanoplatelets from L-NvdW crystals. A comparative analysis of exfoliation techniques is provided for L-vdW and L-NvdW materials, followed by a comprehensive overview of recent advances in ECE methods applied to L-NvdW crystals. The discussion is organized around key categories, including the selective extraction of "M" and "A" layers respectively from MAX phases, decalcification of Zintl phases, and oxide delocalization from metal oxides. It is concluded by highlighting the potential applications of these 2D materials and discussing the challenges and future directions in this evolving field.

• Keywords
• 2D materials, delocalization, electrochemical exfoliation, layered non‐van der Waals,
• Publication type
• Journal Article MeSH
• Review MeSH

Since the debut of silicene in the experimental stage more than a decade ago, the family of two-dimensional elementary layers beyond graphene, called Xenes or transgraphenes, has rapidly expanded to include elements from groups II to VI of the periodic table. This expansion has opened pathways for the engineering of elementary monolayers that are inherently different from their bulk counterparts in terms of fundamental physical properties. Common guidelines for synthesizing Xenes can be categorized into well-defined methodological approaches. On the one hand, bottom-up methods, such as physical epitaxial methods, enable the growth of monolayers, multilayers, and heterostructured Xenes. On the other hand, top-down chemical methods, including topotactic deintercalation and liquid-phase exfoliation, are gaining prominence due to the possibility of massive production. This review provides an extensive view of the currently available synthesis routes for Xenes, highlighting the full range of Xenes reported to date, along with the most relevant identification techniques.

• Publication type
• Journal Article MeSH
• Review MeSH

Energy harvesting and storing by dual-functional photoenhanced (photo-E) energy storage devices are being developed to battle the current energy hassles. In this research work, our investigations on the photoinduced efficiency of germanane (Ge-H) and its functionalized analogue cyanoethyl (Ge-C2-CN) are assessed as photocathodes in photo-E hybrid zinc-ion capacitors (ZICs). The evaluated self-powered photodetector devices made by these germanene-based samples revealed effective performances in photogenerated electrons and holes. The photo-E ZICs findings provided a photoinduced capacitance enhancement of ∼52% (for Ge-H) and ∼26% (for Ge-C2-CN) at a scan rate of 10 mV s-1 under 100 mW cm-2 illumination with 435 nm wavelength. Further characterizations demonstrated that the photo-E ZIC with Ge-C2-CN supply higher specific capacitance (∼6000 mF g-1), energy density (∼550 mWh kg-1), and power density (∼31,000 mW kg-1), compared to the Ge-H. In addition, capacitance retention of photo-E ZIC with Ge-C2-CN is ∼91% after 3000 cycles which is almost 6% greater than Ge-H. Interestingly, the photocharging voltage response in photo-E ZIC made by Ge-C2-CN is 1000 mV, while the photocharging voltage response with Ge-H is approximately 970 mV. The observed performances in Ge-H-based photoactive cathodes highlight the pivotal role of such two-dimensional materials to be applied as single architecture in new unconventional energy storage systems. They are particularly noteworthy when compared to the other advanced photo-E supercapacitors and could even be enhanced greatly with other suitable inorganic and organic functional precursors.

• Keywords
• 2D materials, Zn-ion capacitors, energy storage, germanane, photoactive cathodes, photoenhanced capacitors,
• Publication type
• Journal Article MeSH