Graphene‐Enhanced Nanomaterials for Wall Painting Protection

Abstract

Wall paintings as the highly valuable treasure have been facing severe damaging problems over the years. Ca(OH) 2 as a promising material to protect them has been studied for more than a decade. However, the synthesis methods are still costly, complex, and usually, involve an organic solvent. In addition, problems such as large particle size (>150 nm), slow and weak carbonation, and low consolidation strength for wall paintings remain unsolved. This study demonstrates an unprecedented concept of wall painting protection enabled by graphene-enhanced nanomaterials through strategically synthesizing Ca(OH) 2 /graphene quantum dot (GQD) nanohybrids using a facile and economic aqueous method. The nanohybrids are uniform and small (center distribution at about 80 nm) and show strong adhesivity to wall painting pigments. In addition, the anti-UV absorption ability of the nanohybrids is also a significant advantage. More importantly, the Ca(OH) 2 is fully carbonated into a stable CaCO 3 crystal phase "calcite" because of the GQD, which is crucial in wall painting consolidation. As a result, the graphene-enhanced nanohybrids show superior conservation efficiency compared to as-synthesized Ca(OH) 2 and commercial Ca(OH) 2 materials. The result opens a new direction for protecting cultural heritage using the newly emerging 2D nanomaterials.

Sulfur‐Deficient ZnIn2S4/Oxygen‐Deficient WO3 Hybrids with Carbon Layer Bridges as a Novel Photothermal/Photocatalytic Integrated System for Z‐Scheme Overall Water Splitting

“…Notably, the featured peaks of ZIS, WO, and C are detected at a depth of 2 mm. [38,39] The C-wood thickness is 6 mm, as shown in Figure S21a (Supporting Information). When the system is placed in the water, it is free-floating at the water-air interface and 2 mm of the wood is immersed in the water.…”

Surface chemical functionality of carbon dots: influence on the structure and energy storage performance of the layered double hydroxide

“…Herein, there is a possible reason for the synthesis of the smaller LDH that p-CDs act as a surfactant during the nucleation and growth of LDH, preventing further growth of LDH sheets and assembly into micron-sized owers. [30][31][32] When CDs are introduced into the reaction, they will be overlaid on the petals of LDH. CDs with positive charge has a greater inhibitory effect on the anisotropic growth of the LDH crystal than CDs with negative charge.…”

One-Pot Exfoliation and Functionalization of Zeolite Nanosheets for Protection of Paper-Based Relics

“…The two-dimensional (2D) solid material with weak interlayer interaction provides the application possibility in many new fields requiring special functions and open structure. − After modifying or special processing, monolayer/oligolayer 2D solid/suspension can be achieved, which has more open and flexible structures, well-regulated surface-active sites, − as well as distinctive assembly and functionalized properties, − and they have been used in catalysis, − nanodevices, , and functional films. , In recent years, layered zeolites with monolayer/oligolayer features have been highlighted as new 2D nanoporous solid materials with research significance and practical value. − Until now, the difficulties of preparing monolayer/oligolayer zeolite in an efficient, economical, and green way seriously hinder its sustainable development . Meanwhile, the full potential of 2D zeolites has not yet been unearthed and exploited, and new applications are pending to be discovered as well.…”