Ultra-high-efficiency capture of lead ions over acetylenic bond-rich graphdiyne adsorbent in aqueous solution

Advances of functional graphdiyne in separation and detection

Separation and detection technologies are essential tools for ensuring quality, safety and efficiency across various industries. Graphdiyne (GDY), a carbon material made up of alkyne bonds conjugated with benzene rings to form a planar all-carbon network, is increasingly utilized in the fields of separation and detection. GDY is becoming an ideal separation medium due to its adjustable pore sizes, unique alkyne-rich framework, and easy to be functionalized. On the other hand, GDY shows great potential in detection with the advantages of efficient photoelectric effect, high carrier mobility, and large surface areas to provide active sites. This review summarizes the progress of functional GDY in separation and detection from 2011 to 2024. Various synthesis methods were introduced on improving the properties of GDY in separation and detection. Efforts have increasingly focused on the development of functional GDY in separation functionalities such as magnetic and membranous separations. Moreover, the application of functional GDY in detection technologies are discussed such as electrochemical, spectroanalysis, and dual-mode approaches. Finally, the promising research directions and prospects of functional GDY are discussed to explore further applications in both separation and detection.

In-situ adsorption-coupled-oxidation enabled mercury vapor capture over sp-hybridized graphdiyne

Developing efficient and sustainable carbon sorbent for mercury vapor (Hg0) capture is significant to public health and ecosystem protection. Here we show a carbon material, namely graphdiyne with accessible sp-hybridized carbons (HsGDY), that can serve as an effective "trap" to anchor Hg atoms by strong electron-metal-support interaction, leading to the in-situ adsorption-coupled-oxidation of Hg. The adsorption process is benefited from the large hexagonal pore structure of HsGDY. The oxidation process is driven by the surface charge heterogeneity of HsGDY which can itself induce the adsorbed Hg atoms to lose electrons and present a partially oxidized state. Its good adaptability and excellent regeneration performance greatly broaden the applicability of HsGDY in diverse scenarios such as flue gas treatment and mercury-related personal protection. Our work demonstrates a sp-hybridized carbon material for mercury vapor capture which could contribute to sustainability of mercury pollution industries and provide guide for functional carbon material design.

Metallic 1T/1T' phase TMD nanosheets with enhanced chemisorption sites for ultrahigh-efficiency lead removal

Two-dimensional (2D) materials, as adsorbents, have garnered great attention in removing heavy metal ions (HMIs) from drinking water due to their extensive exposed adsorption sites. Nevertheless, there remains a paucity of experimental research to remarkably unlock their adsorption capabilities and fully elucidate their adsorption mechanisms. In this work, exceptional lead ion (Pb2+) (a common HMI) removal capacity (up to 758 mg g-1) is achieved using our synthesized metallic 1T/1T' phase 2D transition metal dichalcogenide (TMD, including MoS2, WS2, TaS2, and TiS2) nanosheets, which hold tremendous activated S chemisorption sites. The residual Pb2+ concentration can be reduced from 2 mg L-1 to 2 μg L-1 within 0.5 min, meeting the drinking water standards following World Health Organization guideline (Pb2+ concentrations <10 μg L-1). Atomic-scale characterizations and calculations based on density functional theory unveil that Pb2+ bond to the top positions of transition metal atoms in a single-atom form through the formation of S-Pb bonds. Point-of-use (POU) devices fabricated by our reported metallic phase MoS2 nanosheets exhibit treatment capacity of 55 L-water g-1-adsorbent for feed Pb2+ concentration of 1 mg L-1, which is 1-3 orders of magnitude higher than other 2D materials and commercial activated carbon.

Confined Growth of Highly Ordered Metal Atomic Arrays for Seawater Oxidation

Metal atom catalysts have been among the most important research objects due to their specific physical and chemical properties. However, precise control of the anchoring of metal atoms is still challenging to achieve. Cobalt and iridium atomic arrays formed sequentially ordered stable arrays in graphdiyne (GDY) triangular cavities depending on their intrinsic chemical properties and interactions. The success of this method was attributed to multifunctional integration of GDY, enabling selective growth from one to several atoms and various atomic densities. The bimetallic atom arrays show several advantages resulting from reducibility of acetylene bonds, space limiting effect, incomplete charge transfer between GDY and metal atoms, and sp-C hybridized triple bond skeleton. This well-designed system exhibits unprecedented oxygen evolution reaction (OER) performance with a mass activity of 2.6 A mgcat. -1 at a low overpotential of 300 mV, which is 216.6 times higher than the state-of-the-art IrO2 catalyst, and long-term stability.

A novel functionalized graphdiyne oxide membrane for efficient removal and rapid detection of mercury in water

In practice, efficient, rapid and simple removal of Hg(II) from water using nano adsorbents remains an extreme challenge at present. In this work, a novel Hg(II) adsorbent based on functionalized graphdiyne oxide (GDYO-3M) membrane was designed for the purpose of effective and prompt removal of Hg(II) from environmental water for the first time. Through filtration, the proposed GDYO-3M membrane (4 cm diameter size) fulfilled an exceeding 97% removal efficiency in > 10 L water containing 0.1 mg/L Hg(II) within 1 h. Due to the presence of -SH groups, the GDYO-3M membrane demonstrates an excellent selectivity for Hg(II) vs. 14 co-existing metal ions. In the meantime, the GDYO-3M membrane represents a favorable reproducibility (above 95% Hg(II) removal) after 9 successive adsorption-desorption cycles. For the mechanism, it is believed that the active sites in the adsorption process mainly include -SH groups, oxygen-containing functional groups, and alkyne bonds. Further, the GDYO-3M membrane can be utilized as an enrichment approach for sensitive analysis of Hg(II) in water based on energy dispersion X-ray fluorescence spectrometry (ED-XRF), whose detection limit (LOD) reaches 0.2 μg/L within 15 min. This work not only provides a green and efficient method for removing Hg(II), but also renders an approach for rapid, sensitive and portable Hg(II) detection in water.

Microwave-assisted one-pot preparation of magnetic cactus-derived hydrochar for efficient removal of lead(Ⅱ) and phenol from water: Performance and mechanism exploration

A novel magnetic hydrochar derived from cactus cladode (MW-MHC) was successfully synthesized through one-pot microwave-assisted process for efficiently removing lead(Pb)(Ⅱ) and phenol. From batch adsorption experiments, MW-MHC possessed the highest uptake amounts for Pb(Ⅱ) and phenol of 139.34 and 175.32 mg/g within 20 and 60 min, respectively. Moreover, the removal of Pb(Ⅱ) and phenol by MW-MHC remained essentially stable under the interference of different co-existing cations, presenting the excellent adaptability of MW-MHC. After three cycles of regeneration experiments, MW-MHC still had preferable adsorption performance and could be easily recycled, indicating its excellent reusability. Significantly, the uptake mechanisms of Pb(Ⅱ) on MW-MHC were regarded as chemical complexation, pore filling, precipitation, and electrostatic attraction. Meanwhile, the phenol uptake might be dominated by π-π interaction and hydrogen bonding. The above consequences revealed that MW-MHC with high removal performance was a promising adsorbent for remediating wastewater containing heavy metals and organics.

Graphdiyne-Based Multiscale Catalysts for Ammonia Synthesis

Graphdiyne, a sp/sp2 -cohybridized two-dimensional all- carbon material, has many unique and fascinating properties of alkyne-rich structures, large π conjugated system, uniform pores, specific unevenly-distributed surface charge, and incomplete charge transfer properties provide promising potential in practical applications including catalysis, energy conversion and storage, intelligent devices, life science, photoelectric, etc. These superior advantages have made graphdiyne one of the hottest research frontiers of chemistry and materials science and produced a series of original and innovative research results in the fundamental and applied research of carbon materials. In recent years, considerable advances have been made toward the development of graphdiyne-based multiscale catalysts for nitrogen fixation and ammonia synthesis at room temperatures and ambient pressures. This review aims to provide a comprehensive update in regard to the synthesis of graphdiyne-based multiscale catalysts and their applications in the synthesis of ammonia. The unique features of graphdiyne are highlighted throughout the review. Finally, it concludes with the discussion of challenges and future perspectives relating to graphdiyne.