MXene has a unique two-dimensional layered structure, a large specific surface area, and good electrical conductivity, stability, magnetic properties, and mechanical properties. Attributed to its structure and properties, MXene has entered various application fields, such as tumors, antibiotics, batteries, hydrogen storage, sensors, electromagnetic shielding, etc. Studies on MXene are implemented in various fields. The preparation methods, surface functional groups, and the preparation technology of composite materials directly affect the performance of MXene and determine its application fields. As significantly important issues, many influencing factors exist in the preparation process of MXene and the process of composite material design, which directly impact the properties and applications of MXene. This paper investigates and analyzes the factors influencing the preparation, properties, and application of MXene, explores the research progress of MXene, and provides critical insights for synthesizing and modifying effective MXene adsorbents. Moreover, this review discusses the influencing factors on applications, i.e., CO₂ reduction, energy storage, heavy metal removal, etc., and compares key factors, including surface modification, pH, reaction time, and adsorption capacity, etc. Furthermore, this review provides an overview on current status and offers recommendations.

In the perspective of energy sustainability, biomass is the widely used renewable domestic energy with low cost and easy availability. Increasing studies have reported the health impacts of toxic substances from biomass burning emissions. To make proper use of biomass as residential solid energy, the evaluation of its health risks and environmental impacts is of necessity. Empirical studies on the characteristics of toxic emissions from biomass burning would provide scientific data and drive the development of advanced technologies. This review focuses on the emission of four toxic substances, including heavy metals, polycyclic aromatic hydrocarbons (PAHs), elemental carbon (EC), and volatile organic compounds (VOCs) emitted from biomass burning, which have received increasing attention in recent studies worldwide. We focus on the developments in empirical studies, methods of measurements, and technical factors. The influences of key technical factors on biomass burning emissions are combustion technology and the type of biomass. The methods of sampling and testing are summarized and associated with various corresponding parameters, as there are no standard sampling methods for the biomass burning sector. Integration of the findings from previous studies indicated that modern combustion technologies result in a 2–4 times reduction, compared with traditional stoves. Types of biomass burning are dominant contributors to certain toxic substances, which may help with the invention or implementation of targeted control technologies. The implications of previous studies would provide scientific evidence to push the improvements of control technologies and establish appropriate strategies to improve the prevention of health hazards.

Graphene and its derivatives (GDs) have been applied in many fields, like photocatalysts, sensors, and biomedical delivery, due to its excellent physicochemical properties. However, the widespread use of GDs has significantly increased human exposure to these materials. Some health risks of exposure to GDs have been identified, including organ fibrosis, inflammation, DNA damage, etc. Given that graphene is a novel concern, we especially emphasized the various exposure pathways and potential health risks of exposure to GDs. People get exposed to GDs mainly through inhalation, ingestion, dermal contact, etc. GDs could transfer to the circular system of people and accumulate in blood, cells, and major organs. GDs exposure could induce organ and cell inflammatory responses and damage, such as disrupted kidney function, declined cell vitality, cytotoxicity, etc. These changes at the organ and cell levels might lead to adverse tangible influences on people, like decreased locomotor activity, the accelerated aging process, and even abnormal offspring development. We also summarized the characterization and detection methods of GDs. In addition, we compared the studies of exposure to dust and GDs in the aspects of health risks and study methods. This review could offer a comprehensive summary related to GDs and provide helpful references for further graphene-related studies.

The Songhua River is one of the most populated and oldest industrial areas in Northeast China. To understand the sources and distribution of polycyclic aromatic hydrocarbons and their derivatives, such as 16 priority (PAHs), 33 methylated (Me-PAHs), and 12 nitrated (NPAHs) in river water and sediment, were noticed. The concentrations of ∑PAHs, ∑Me-PAHs, and ∑NPAHs in river water scaled from 135 to 563, 9.36 to 711, and 1.26 to 64.7 ng L⁻¹, with mean values of 286, 310, and 17.9 ng L⁻¹, and those in sediments were from 35.8 to 2000 ng g⁻¹, 0.62 to 394 ng g⁻¹, and 0.28 to 176 ng g⁻¹ (dry weight) with mean values of 283, 103, and 21.7 ng g⁻¹. The compositions proved that two-ring and three-ring compounds of PAHs, NPAHs, and four-ring, six-ring of Me-PAHs were prevalent in water samples; in contrast, four-ring dominated in sediments. Principal components analysis (PCA) and diagnostic ratios confirmed that pollutant source was mixed petrogenic and pyrogenic origin. The fugacity fraction (ƒƒ) was also calculated to explain the trend of sediment–water exchange, high ƒƒ values found in summer, for most HMW PAHs and Me-PAHs that these substances acted as a secondary source of emissions from sediment to water. The risk assessment for water was categorized as high.