Ti₃C₂T_x-Based Three-Dimensional Hydrogel by a Graphene Oxide-Assisted Self-Convergence Process for Enhanced Photoredox Catalysis

Abstract

Assembly of two-dimensional (2D) layered structures into three-dimensional (3D) macroscopic hydrogel has been an enduring attracting research theme. However, the anisotropic intersheet cross-linking to form Ti3C2T x MXene-based hydrogel remains intrinsically challenging because of the superior hydrophilic nature of 2D Ti3C2T x . Herein, Ti3C2T x MXene is ingeniously assembled into the 3D macroscopic hydrogel under mild conditions by a graphene oxide (GO)-assisted self-convergence process. During the process, GO is reduced to reduced graphene oxide (RGO) by virtue of the reduction ability of Ti3C2T x , leading to the partial removal of hydrophilic oxygen-containing groups and an increase of the hydrophobicity and the π-conjugated structures of RGO, which enables the assembly of RGO into a 3D RGO framework. Simultaneously, Ti3C2T x is self-converged to be incorporated into the RGO framework by intimate interfacial interactions, thereby generating Ti3C2T x -based hydrogel. The hydrogel with interconnected porous structure holds great potential as a promising material platform for photoredox catalysis. With the incorporation of Eosin Y photosensitizer, the functional Ti3C2T x -based hydrogel exhibits enhanced photoactivity compared to the powder counterpart and features easy operability. This work enriches the rational utilization of GO/MXene colloid chemistry to design Ti3C2T x MXene-based hydrogels with improved overall efficacy in practical applications.

Fast Gelation of Ti3C2Tx MXene Initiated by Metal Ions

“…Different from the above 2D materials, MXenes prepared by selective etching contain a number of functional groups on their surfaces and edges (F − , O, and OH) show good dispersion in aqueous solution and have the potential to build 3D MXene‐based assemblies by solution‐based techniques. With the GO as the linker, 3D graphene/MXene hybrid monoliths have been assembled in solution with a low temperature heating . In the assembly processes, the laminated MXene domains interacted with the π‐conjugated GO sheets which then guided the formation of the 3D structure.…”

Anchoring CuO Nanoparticles On C, N‐Codoped G‐C3N4 Nanosheets from Melamine‐Entrapped MOF Gel for High‐Efficiency Oxygen Evolution

“…Powder X‐ray diffraction (PXRD) diffraction peaks for the intermediate product at 14.9°, 28.9°, 29.8° and 30.3° index to (011), (112), (013) and (211) planes (JCPDS No. 39‐1950), indicate the existence of Mel (Figure S2), while the peaks at 4.1, 8.0 and 12.1 match with those of simulated Cu(II)‐MOF single crystal (112), (202) and (105) planes, suggesting that Mel in Cu(II)‐TDPAT@Mel doesn′t change the MOF framework, but are incorporated into the Cu(II)‐MOF pores and loaded on the outer surfaces of the MOF nanocrystals . When heated to 300 °C, the rod‐shaped crystals seen at 140 °C have self‐assembled into nanosheet bundles (Figure c and d).…”

“…Subsequently, these grew up into interconnected rod-shaped crystals (< 40 nm in diameter) when heated to 140°C (Figure 1a 202) and (105) planes, [28] suggesting that Mel in Cu(II)-TDPAT@Mel doesn't change the MOF framework, but are incorporated into the Cu(II)-MOF pores and loaded on the outer surfaces of the MOF nanocrystals. [29,30] When heated to 300°C, the rod-shaped crystals seen at 140°C have self-assembled into nanosheet bundles (Figure 1c and d). Significantly, the further oxidation pyrolysis at 350°C for 3 h in air resulted in producing larger nanosheets with a size of~1.0 μm × 1.0 μm anchored on Ni-f ( Figure 1f), which assembly may reduce specific surface energy.…”

A Mechanism Investigation of how the Alloying Effect Improves the Photocatalytic Nitrate Reduction Activity of Bismuth Oxyhalide Nanosheets

“…Generally, the photocatalytic properties of semiconductors are strongly related to their crystallinity and surface properties, such as morphology, specific surface area, as well as surface feature. [33][34][35][36][37][38][39] Since the samples have similar morphological structures and specific surface areas, we explored their surface features. Herein, we investigated the atomic arrangement of the surface of BiOCl n Br 1-n .…”