Novel two-dimensional ZnO/Ti₃C₂T_x hybrid photocatalysts with modified surface areas were prepared using a simple calcination technique. The microstructures, crystalline features, and bonding states of the ZnO structure-covered Ti₃C₂T_x MXenes were closely characterized using various tools. The photoluminescence intensity of the hybrid photocatalyst was greatly reduced compared to the pristine ZnO, while its Brunauer-Emmett-Teller (BET) surface area increased by more than 100 times. Under solar light illumination, the photocatalytic degradation efficiency of the hybrid photocatalyst for organic pollutants (MO, RhB) appeared to be three-fold larger as compared to pristine ZnO. The superb photocatalytic performance of the photocatalyst was attributed to several factors, such as ideal band alignment, Schottky barrier formation, and large surface area. Moreover, the ZnO/Ti₃C₂T_x hybrid photocatalyst showed excellent cycling stability. These results suggest that the novel hybrid structure may be a potential candidate for removing organic pollutants in wastewater.

A representative of titanium carbide MXene, Ti₃C₂T_x is a promising candidate for high performance gas sensing and has attracted significant attention. However, MXene naturally has a multilayer structure with low porosity, which prevents its gas-sensing activity. Zinc oxide (ZnO) has long been utilized as a gas detector. Despite its good response to multiple gases, high operation temperature has limited its widespread use as a gas-sensing material. In this study, a room-temperature toxic gas sensor was prepared from ZnO/Ti₃C₂T_x MXene nanocomposite consisting of 2D few-layered MXene and 1D ZnO nanoparticles. A simple technique for synthesizing the nanocomposite was established. The physicochemical properties of the nanocomposite were fine-controlled with more active sites and higher porosity. The sensitivity and gas-selectivity of the sensing material were closely examined. The nanocomposite showed enhanced response and recovery behaviors to toxic gases, which outperformed pure Ti₃C₂T_x MXene and pure ZnO. This study offers a practical strategy by which to increase the gas-sensing performance of Ti₃C₂T_x MXene, and expands comprehensive understanding of the gas-sensing process of ZnO/Ti₃C₂T_x p-n heterostructure.

Sensing of hazardous gases has an important role in ensuring safety in a variety of industries as well as environments. Mainly produced by the combustion of fossil fuels and other organic matter, ethanol is a dangerous gas that endangers human health and the environment. Stability and sensing sensitivity are major considerations when designing gas sensors. Here, a superior ethanol sensor with a high response and fast recovery was synthesized by “wrapping” CdS nanoparticles on metallic Ti₃C₂T_x MXene using a simple method. CdS nanoparticles were uniformly covered on the Ti₃C₂T_x MXene surface, forming a “rice crust”-like heterostructure. The sensor displayed good detection of ethanol gas at room temperature. Response signals up to 31% were obtained for ethanol molecules (20 ppm) with quick recovery (41 s). The performance of the ethanol sensor was evaluated across a range of concentrations (5–100 ppm) and relative humidity (60% and 90% RH) at room temperature. Our method could open up a new strategy for the development of ethanol sensors.

Biphasic calcium phosphate (BCP) is a bioceramic widely used in hard tissue engineering for bone replacement. BCP consists of β-tricalcium phosphate (β-TCP) – a highly soluble and resorbable phase – and hydroxyapatite (HA) – a highly stable phase, creating a balance between solubility and resorption, optimally supporting cell interactions and tissue growth. The β-TCP/HA ratio significantly affects the resorption, solubility, and cellular response, with a higher β-TCP ratio increasing resorption due to its solubility. BCP is commonly synthesized by calcining calcium-deficient apatite (CDA) at temperatures above 700 °C via direct or indirect methods. This study investigated the effects of pH and sintering temperature on BCP synthesized via wet precipitation, aiming to achieve an 80/20 β-TCP/HA ratio, which is known to be optimal for bone regeneration. By maintaining a constant Ca/P precursor ratio of 1.533, the optimal conditions were determined to be a pH of 5.5–6 and a sintering temperature of 900 °C, chosen to balance material stability and solubility. The successful synthesis was confirmed using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. At the same time, the material's physical and chemical properties were further characterized through scanning electron microscopy (SEM) and degradation studies in a simulated body fluid (SBF). In vitro tests demonstrated excellent cytocompatibility and osteogenic differentiation, while in vivo studies on rabbit femur defects demonstrated significant bone regeneration, with bone-to-tissue volume ratios exceeding 50% within four weeks. These results highlight the potential of BCPs in bone tissue engineering and biomaterials research.

Two-dimensional (2D) inorganic compounds, MXenes, are the most promising candidate for chemical sensors and environmental remediation. Since the first synthesis of Ti₃C₂T_x MXene from the Ti₃AlC₂ MAX phase in 2011, 2D materials have been attracting significant attention from a wide range of scientific communities because of their unique physicochemical properties. The attractive properties of MXenes motivated us to explore the new wave of front-end research and applications. Over the past 12 years, there have been more than 10,000 theoretical and experimental studies on MXenes. All these publications have primarily focused on Ti₃C₂T_x MXene because of its fascinating material properties and tunability towards target applications. To provide readers with a fundamental understanding of this emerging 2D material, this review discusses the recent trends in the design of Ti₃C₂T_x MXene for gas sensors and energy harvesting applications. For the most updated information, this review focuses on important findings and applications reported in the last decade.