Ahsanullah University of Science and Technology

Intercalation of gases and metal species beneath graphene supported on transition-metal substrates has emerged as a powerful strategy for tuning graphene–substrate interactions and tailoring its electronic, chemical, and mechanical properties. Numerous studies have investigated these phenomena using surface-sensitive techniques, including X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and low-energy electron diffraction (LEED). This review examines the intercalation of oxygen, carbon monoxide, and hydrogen, with particular emphasis on graphene grown on Ir(111). Oxygen intercalation proceeds under ultrahigh-vacuum conditions through atomic oxygen formation on bare Ir terraces and requires elevated temperatures (~355 K), whereas hydrogen intercalation occurs at much lower temperatures (~140 K). CO intercalation takes place near room temperature but requires millibar-range pressures. In all cases, substrate step edges and graphene flake boundaries serve as critical pathways for intercalant penetration. These structural features have been consistently identified as key entry points for intercalant diffusion. Intercalation provides an additional degree of freedom for controlling the properties of 2D materials, enabling modulation of electrical conductivity, thermoelectric response, and catalytic activity. The process significantly modifies the electronic, chemical, and mechanical characteristics of the graphene layer, while also partially decoupling it from the underlying substrate. Given these effects, gas intercalation beneath graphene represents a promising strategy for applications in catalysis, sensing, and energy storage. Intercalation can also be used to partially separate the graphene overlayer from the underlying metal, leading to considerable enhancement of electronic, chemical and mechanical properties. This review highlights the fundamental mechanisms and technological potential of gas (O 2 , H 2 , and CO) intercalation beneath graphene for applications in catalysis, sensing, energy storage, and next-generation graphene-based devices.

Oysters are effective bioindicators of aquatic contamination. Their filter-feeding behavior causes them to bioaccumulate heavy metals and emerging contaminants from coastal waters. This poses both ecological and human health risks through seafood consumption. This study evaluated trace metal contamination, microbiological quality, and human health risk in Crassostrea belcheri from the Cox's Bazar coast, Bangladesh. Twelve trace metals were quantified in the soft tissue. Na, K, and Ca dominated the metal profile, followed by Zn, Mg, Fe, Cu, Mn, Ni, Cr, Pb, and Cd, which occurred at comparatively low levels. Most metals exceeded Bangladesh's national shellfish contamination guideline, except Cd. This points to a broader baseline contamination burden, even where dietary-intake indices suggested low risk. Estimated Daily Intake values for all metals stayed within permissible limits. This corresponds to negligible non-carcinogenic hazard. However, carcinogenic risk estimates for Cd, Cr, and Ni exceeded acceptable thresholds. This indicates a real long-term cancer risk from chronic consumption, despite the reassuring non-carcinogenic profile. Escherichia coli was detected in microbiological screening of collected oysters, whereas Vibrio cholerae and Salmonella spp. were not detected in any of the analyzed samples. This suggests a relatively low burden among the tested pathogens, though other microbial hazards cannot be ruled out. Trace metal contamination in C. belcheri poses a greater long-term health concern than national guidelines or acute intake thresholds alone would suggest. Regular monitoring is recommended to protect consumer health and support quality assurance for export markets that depend on this regionally important but understudied resource.

Intercalation of gases and metal species beneath graphene supported on transition-metal substrates has emerged as a powerful strategy for tuning graphene–substrate interactions and tailoring its electronic, chemical, and mechanical properties. Numerous studies have investigated these phenomena using surface-sensitive techniques, including X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and low-energy electron diffraction (LEED). This review examines the intercalation of oxygen, carbon monoxide, and hydrogen, with particular emphasis on graphene grown on Ir(111). Oxygen intercalation proceeds under ultrahigh-vacuum conditions through atomic oxygen formation on bare Ir terraces and requires elevated temperatures (~355 K), whereas hydrogen intercalation occurs at much lower temperatures (~140 K). CO intercalation takes place near room temperature but requires millibar-range pressures. In all cases, substrate step edges and graphene flake boundaries serve as critical pathways for intercalant penetration. These structural features have been consistently identified as key entry points for intercalant diffusion. Intercalation provides an additional degree of freedom for controlling the properties of 2D materials, enabling modulation of electrical conductivity, thermoelectric response, and catalytic activity. The process significantly modifies the electronic, chemical, and mechanical characteristics of the graphene layer, while also partially decoupling it from the underlying substrate. Given these effects, gas intercalation beneath graphene represents a promising strategy for applications in catalysis, sensing, and energy storage. Intercalation can also be used to partially separate the graphene overlayer from the underlying metal, leading to considerable enhancement of electronic, chemical and mechanical properties. This review highlights the fundamental mechanisms and technological potential of gas (O2, H2, and CO) intercalation beneath graphene for applications in catalysis, sensing, energy storage, and next-generation graphene-based devices.

The demand for electricity continues to increase with economic growth and increasing end-use electrification, particularly in the transport sector. Despite ongoing progress, achieving Sustainable Development Goal (SDG) 7 by 2030, which aims to provide affordable and clean energy for all, remains uneven and structurally constrained. Electric vehicle (EV)-integrated community microgrids (MGs), operating in grid-connected or islanded modes are a promising solution that combines distributed energy resources, local electricity generation options and mobile energy storage systems (ESSs) through EV fleets. However, the high penetration of renewable energy resources, EVs and battery ESSs introduces significant challenges to system stability, power flow and operational reliability. This review provides a comprehensive assessment of recent developments in EV-integrated community MGs, energy management, decentralized EV fleet coordination and bidirectional EV charging/discharging into the electricity network. It also provides a framework for integrating MGs, EVs, and renewables, including grid-to-vehicle (G2V) charging, bidirectional vehicle-to-grid (V2G) and vehicle-to-everything (V2X) applications, to enhance grid flexibility and ancillary services. It further discusses the optimization mechanisms, control frameworks and their applications within the MG environment. In addition, the review evaluates the contribution of EV-integrated community MGs toward achieving SDG 7 in sustainable community energy systems. The analysis also addresses existing technical, economic, social acceptance and regulatory challenges that hinder large-scale deployments. The study outlines future research directions and proposes a conceptual framework for researchers and policymakers, offering actionable pathways to accelerate the global clean energy transition and support the achievement of the UN 2030 Agenda for Sustainable Development.

Bismuth ferrite (BFO) has emerged as a promising multifunctional material for electronic applications. This study demonstrates that 10