The Quest for Two-Dimensional MBenes: From Structural Evolution to Solar-Driven Hybrid Systems for Water-Fuel-Energy Generation and Phototherapy.

The field of 2D materials has advanced significantly with the emergence of MBenes, a new material derived from the MAX phases family, a novel class of materials that originates from the MAX phases family. Herein, this article explores the unique characteristics and morphological variations of MBenes, offering a comprehensive overview of their structural evolution. First, the discussion explores the evolutionary period of 2D MBenes associated with the several techniques for synthesizing, modifying, and characterizing MBenes to tailor their structure and enhance their functionality. The focus then shifts to the defect chemistry of MBenes, electronic, catalytic, and photothermal properties which play a crucial role in designing multifunctional solar-driven hybrid systems. Second, the recent advancements and potentials of 2D MBenes in solar-driven hybrid systems e.g. photo-electro catalysis, hybrid solar evaporators for freshwater and thermoelectric generators, and phototherapy, emphasizing their crucial significance in tackling energy and environmental issues, are explored. The study further explores the fundamental principles that regulate the improved photocatalytic and photothermal characteristics of MBenes, highlighting their promise for effective utilization of solar energy and remediation of the environment. The study also thoroughly assesses MBenes' scalability, stability, and cost effectiveness in solar-driven systems. Current insights and future directions allow researchers to utilize MBenes for sustainable and varied applications. This review regarding MBenes will be valuable to early researchers intrigued with synthesizing and utilizing 2D materials for solar-powered water-energy-fuel and phototherapy systems.

Biomass-Printed Hybrid Solar Evaporator Derived from Bio-polluted Invasive Species, a Potential Step toward Carbon Neutrality.

Biomass-based photothermal conversion is of great importance for solar energy utilization toward carbon neutrality. Herein, a hybrid solar evaporator is innovatively designed via UV-induced printing of pyrolyzed Kudzu biochar on hydrophilic cotton fabric (KB@CF) to integrate all parameters in a single evaporator, such as solar evaporation, salt collection, waste heat recovery for thermoelectricity, sieving oil emulsions, and water disinfection from microorganisms. The UV-induced printed fabric demonstrates stronger material adhesion as compared to the conventional dip-dry technique. The hybrid solar evaporator gives an enhanced evaporation rate (2.32 kg/m2 h), and the complementary waste heat recovery system generates maximum open-circuit voltage (Vout ∼ 143.9 mV) and solar to vapor conversion efficiency (92%), excluding heat losses under one sun illumination. More importantly, 99.98% of photothermal-induced bacterial killing efficiency was achieved within 20 min under 1 kW m-2 using the hyperthermia effect of Kudzu biochar. Furthermore, numerical heat-transfer simulations were performed successfully to analyze the enhanced interfacial heat accumulation (75.3 °C) and heat flux distribution of the thermoelectric generators under one sun. We firmly believe that the safe use of bio-polluted invasive species in hybrid solar-driven evaporation systems eases the environmental pressure toward carbon neutrality.

Nanocomposite-Enhanced Efficient Evaporation System for Solar-Driven Seawater Desalination-An Optimized Design for Clean Water Production.

Solar-driven evaporation is a promising technology for desalinating seawater and wastewater without mechanical or electrical energy. The approaches to obtaining fresh water with higher evaporation efficiency are essential to address the water-scarcity issue in remote sensing areas. Herein, we report a highly efficient solar evaporator derived from the nanocomposite of anatase TiO2/activated carbon (TiO2/AC), which was coated on washable cotton fabric using the dip-dry technique for solar water evaporation. The ultra-black fabric offers enhanced solar absorption (93.03%), hydrophilic water transport, and an efficient evaporation rate of 1.65 kg/m2h under 1 kW m-2 or one sun solar intensity. More importantly, the sideways water channels and centralized thermal insulation of the designed TiO2/AC solar evaporator accumulated photothermal heat at the liquid and air interface along with an enhanced surface temperature of 40.98 °C under one sun. The fabricated solar evaporator desalinated seawater (3.5 wt%) without affecting the evaporation rates, and the collected condensed water met the standard of drinking water set by the World Health Organization (WHO). This approach eventually enabled the engineering design groups to develop the technology pathways as well as optimum conditions for low-cost, scalable, efficient, and sustainable solar-driven steam generators to cope with global water scarcity.

Low-cost green recyclable biomaterial for energy-dependent electrical switching and intact biofilm with antibacterial properties.

A highly cost-effective recycled biomaterial extracted from lime peel has been made biocompatible and has been coated on a commercial fluorine-doped tin oxide (FTO) substrate of glass using the spin coating method. Structural, morphologic, electronic, and antibacterial measurements were thoroughly characterized as a green biomaterial thin film using X-rays (XRD), PL, FTIR, Raman, SEM, HRTEM, AFM, I-V, and antibacterial diffusion techniques. The comprehensive analysis of structures of recyclable waste in the form of lime peel extract (LPE) as thin films showed the crystalline cellulose structure that corresponds to the lattice fringe (0.342 nm) exposed by HRTEM. The K+1 interstitial active sites or vacancies in LPE/FTO thin films are confirmed by the PL spectra that show important evidence about conduction mechanisms, and hence facilitates Ag+1 ion migration from the top to the bottom electrode. The AFM investigations revealed the minor surface roughness (169.61 nm) of the LPE/FTO film, which controls the current leakage that is associated with surface defects. The designed memory cell (Ag/LPE/FTO) exhibits stable, reproducible electrical switching under low operational voltage and is equipped with excellent retention over 5 × 103 s. Furthermore, owing to presence of flavonoids and their superior antioxidant nature, lime peel extract powder shows tremendous antimicrobial activity against gram-positive and Gram-negative bacterial strains.