Sonochemical synthesis of photocatalysts and their applications

Transition metal carbides and nitrides (MXene), as a promising class of two-dimensional inorganic compounds, are materials composed of a few atomic layers of transition metal carbides, nitrides, or carbonitrides. The...

2D Single- and Few-Layered MXene: Synthesis, applications and perspectives

Highly-dispersed nano-TiB2 derived from the two-dimensional Ti3CN MXene for tailoring the kinetics and reversibility of the Li-Mg-B-H hydrogen storage material

Metals and alloys are essential in modern society, and are used in our daily activities. However, they are prone to corrosion, with the conversion of the metal/alloy to its more thermodynamically-favored oxide/hydroxide phase. These undesirable corrosion reactions can lead to the failure of metallic components. Consequently, corrosion-protective technologies are now more important than ever, as it is essential to reduce the waste of valuable resources. In this review, we consider the role of emerging 2D materials and layered materials in the development of a corrosion protection strategy. In particular, we focus on the materials beyond graphene, and consider the role of transition metal dichalcogenides, such as MoS2, MXenes, layered double hydroxides, hexagonal boron nitride and graphitic carbon nitride in the formulation of effective and protective films and coatings. Following a short introduction to the synthesis and exfoliation of the layered materials, their role in corrosion protection is described and discussed. Finally, we discuss the future applications of these 2D materials in corrosion protection.

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Emerging Layered Materials and Their Applications in the Corrosion Protection of Metals and Alloys

Fabrication TiO2 with conductive two-dimensional materials is an effective strategy to improve its photocatalytic activity. Herein, a well-defined carbon-doped TiO2/Ti3C2 heterojunction is constructed via in situ controllable oxidation of Ti3C2 MXene in carbon dioxide. The formed C-doped TiO2 nanoparticles as the photocatalyst uniformly disperse on the surface of Ti3C2 MXene and generate electrons and holes under irradiation. The two-dimensional Ti3C2 MXene, owing to its excellent conductivity, acts as the electron transport channels and accelerates the separation of photogenerated electrons and holes. Meanwhile, due to its large specific surface area and good solubility, Ti3C2 MXene may facilitate to enhance the adsorption of pollutant on the photocatalyst as well as the absorption of photocatalyst for visible light. Therefore, the unique merits of TiO2 and Ti3C2 MXene are integrated to deliver the composites high photocatalytic activity. The proper content of Ti3C2 MXene and TiO2 in the composite is crucial for enhancing the photocatalytic performance, which can be effectively tuned by varying the oxidation temperature. In this work, C-doped TiO2/Ti3C2 oxidized at 400 °C presents the optimum photocatalytic performance. 

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MXene-derived C-doped TiO2/Ti3C2 heterojunction as a high-performance visible-light photocatalyst

Low-dimensional MXenes as noble metal-free co-catalyst for solar-to-fuel production: Progress and prospects

Developing highly efficient, robust, and noble metal‐free photocatalytic systems is essential for the large‐scale implementation of solar‐to‐chemical energy conversion. Herein, a novel sandwich‐like hierarchical heterostructure of Ti3C2 MXene/WO3 is created by in situ growth of ultrathin WO3 nanosheets onto the surface of few‐layer Ti3C2 nanosheets via a one‐pot solvothermal synthesis strategy. The resultant Ti3C2/WO3 heterostructure holds a large interface contact area, an intimate electronic interaction, and a short carrier migration distance, which is beneficial for bulk‐to‐surface and interfacial charge transfer. Meanwhile, the excellent electrical conductivity of Ti3C2 and the Schottky junction at the interface of WO3 and Ti3C2 expedites the spatial charge separation and transportation. As expected, the as‐prepared Ti3C2/WO3 nanohybrids exhibit a superior visible‐light‐driven photoactivity and stability toward tetracycline hydrochloride (TC) decomposition. Across a range of Ti3C2 concentrations, 3 wt% Ti3C2/WO3 achieves the greatest photodegradation rate of 16.08 × 10−3 min−1 that is approximately ninefold larger than that of pristine WO3. In addition to the underlying photocatalytic mechanism, three TC degradation pathways are identified, highlighting the important roles of ·O2− and h+. This study shows the potential of earth‐abundant MXene family materials in the fabrication of high‐performance and low‐cost photocatalysts applicable for environment purification.

Shi-yi Xue

Papers

Low-dimensional MXenes as noble metal-free co-catalyst for solar-to-fuel production: Progress and prospects

Noble Metal‐Free Heterojunction of Ultrathin Ti3C2 MXene/WO3 for Boosted Visible‐Light‐Driven Photoreactivity