Fluorescent nanodiamond is a new nanomaterial that possesses several useful properties, including good biocompatibility1, excellent photostability1,2 and facile surface functionalizability2,3. Moreover, when excited by a laser, defect centres within the nanodiamond emit photons that are capable of penetrating tissue, making them well suited for biological imaging applications1,2,4. Here, we show that bright fluorescent nanodiamonds can be produced in large quantities by irradiating synthetic diamond nanocrystallites with helium ions. The fluorescence is sufficiently bright and stable to allow three-dimensional tracking of a single particle within the cell by means of either one- or two-photon-excited fluorescence microscopy. The excellent photophysical characteristics are maintained for particles as small as 25 nm, suggesting that fluorescent nanodiamond is an ideal probe for long-term tracking and imaging in vivo, with good temporal and spatial resolution.

Mass production and dynamic imaging of fluorescent nanodiamonds

Two-dimensional MXenes: From morphological to optical, electric, and magnetic properties and applications

Unveiling the active sites of graphene-catalyzed peroxymonosulfate activation

MXenes, a bourgeoning class of 2D transition metal carbides, are of considerable interest in catalysis due to their rich surface chemistry, tunable electronic structures, and thermal stability. Here, recent conceptual advances in applying MXenes and their nanocomposites in (photo)electrocatalysis and conventional heterogeneous catalysis are highlighted. In addition, the nature of active sites in the MXene-based catalysts are discussed and the significance and challenges in the future development of catalysts using MXenes as the platforms are summarized.

2D Early Transition Metal Carbides (MXenes) for Catalysis.

Metal-free catalysis has gained broad interest for sustainable chemistry. Carbocatalysis is one green option for catalytic transformation in the gas phase as well as in the liquid phase. This is documented by the numerous reports on gas phase dehydrogenation and selective oxidation where carbon can be successful alternatives to metal oxide systems. Carbocatalysis for liquid phase reactions, especially for organic synthesis, is an emerging research discipline and has been under rapid development in recent years. This review provides a critical analysis on the state-of-the-art carbocatalysts for liquid phase reactions, with the focus on the underlying mechanisms, the advantages and limitations when only carbon, without any intentional metal species (supported systems), is used to catalyze some traditional liquid phase reactions.

Carbocatalysis in Liquid-Phase Reactions.

A nanodiamond/CNT–SiC monolith as a novel metal free catalyst for ethylbenzene direct dehydrogenation to styrene

Two-dimensional materials (such as graphene, MXenes) usually perform remarkably well as catalysts in comparison with their three-dimensional counterparts In this work, Ti3AlC2-derived Ti3C2Tx MXene (T = O, OH, F) was prepared and employed in the direct dehydrogenation of ethylbenzene A 92 μmol m–2 h–1 reactivity and a 40 h stability with almost no deactivation were observed, which is much better than those of the previously reported nanocarbon catalysts The graphene-like layered structure and the C–Ti–O termination groups induced by the preparation process were thought to account for the good catalytic performance of Ti3C2Tx MXene from both experimental and computational perspectives The discovery expands the application of two-dimensional MXenes and provides more choices in exploring high-activity catalysts for hydrocarbon dehydrogenation reactions

Ti3C2Tx MXene Catalyzed Ethylbenzene Dehydrogenation: Active Sites and Mechanism Exploration from both Experimental and Theoretical Aspects

Carbon is emerging as an important metal-free catalyst for multiple types of heterogeneous catalysis, including thermocatalysis, photocatalysis, and electrocatalysis. However, the study of mechanisms for carbon catalysis has been impeded at an early stage due to the lack of quantitative research, especially the intrinsic kinetics (e.g., intrinsic TOF). In many carbon-catalyzed reactions, the surface oxygenated groups were found to be the active sites. Recently, we have shown that these oxygenated groups could be identified and quantified via poisoning by small organic molecules; however, these small molecules were toxic. As most of the oxygenated groups are acidic groups, they could also be identified and quantified with respect to the acid properties. More importantly, the method based on acid properties is very green and environmentally benign, because only inorganic bases are added. In this work, the acid properties of carbon nanotubes (CNTs) treated by concentrated HNO3 were thoroughly studied by mass...

Jiangyong Diao

Papers

A nanodiamond/CNT–SiC monolith as a novel metal free catalyst for ethylbenzene direct dehydrogenation to styrene

Ti3C2Tx MXene Catalyzed Ethylbenzene Dehydrogenation: Active Sites and Mechanism Exploration from both Experimental and Theoretical Aspects

Acid Properties of Nanocarbons and Their Application in Oxidative Dehydrogenation

Porous graphene-based material as an efficient metal free catalyst for the oxidative dehydrogenation of ethylbenzene to styrene

Cooperative Sites in Fully Exposed Pd Clusters for Low-Temperature Direct Dehydrogenation Reaction