Wood-based panels, which contain wood raw materials along with urea-formaldehyde (UF) or phenol-formaldehyde (PF) resins, can increase the indoor air concentration of formaldehyde. Formaldehyde can stimulate the upper respiratory mucosa and cross-linking reaction with cell proteins and DNA, and this can result in degeneration and necrosis of respiratory cells and damaged cell proliferation. Formaldehyde can induce health hazards such as nasal cancer, leukemia, and destruction of the reproductive system. Acetaldehyde dehydrogenase 5 (ADH5) in the body cooperates with Fanconi anaemia complementation group D2 (FANCD2) to quickly metabolize formaldehyde into formate and maintain the balance of endogenous formaldehyde. However, when both ADH5 and FANCD2 proteins have defects or mutations, damaged DNA repair failure and cell proliferation induce a variety of health diseases. The damage has been found in the upper respiratory area, not on distal body tissues such as liver, kidney, and bone marrow. Meanwhile epidemiological survey has not shown a positive correlation between formaldehyde and health hazards. It is recommended that the use of wood formaldehyde-based products should be reduced, and pathogenesis genes and damage repair mechanism should be studied systematically and deeply to develop gene drugs to remove excess formaldehyde and activate the damage gene repair mechanism in the future.

Water pollution has spurred the development of membrane separation technology as a potential means of solving the issue. In contrast to the irregular and asymmetric holes that are easily made during the fabrication of organic polymer membranes, forming regular transport channels is essential. This necessitates the use of large-size, two-dimensional materials that can enhance membrane separation performance. However, some limitations regarding yield are associated with preparing large-sized MXene polymer-based nanosheets, which restrict their large-scale application. Here, we propose a combination of wet etching and cyclic ultrasonic-centrifugal separation to meet the needs of the large-scale production of MXene polymers nanosheets. It was found that the yield of large-sized Ti₃C₂T_x MXene polymers nanosheets reached 71.37%, which was 2.14 times and 1.77 times higher than that prepared with continuous ultrasonication for 10 min and 60 min, respectively. The size of the Ti₃C₂T_x MXene polymers nanosheets was maintained at the micron level with the help of the cyclic ultrasonic-centrifugal separation technology. In addition, certain advantages of water purification were evident due to the possibility of attaining the pure water flux of 36.5 kg m⁻² h⁻¹ bar⁻¹ for the Ti₃C₂T_x MXene membrane prepared with cyclic ultrasonic-centrifugal separation. This simple method provided a convenient way for the scale-up production of Ti₃C₂T_x MXene polymers nanosheets.