Non-extra-artificial destructive detection of trace residual detached wall painting pigments is an important prerequisite for wall paintings restoration work. As the amount available for detection of artifacts is relatively small, the relevant information must be derived through microanalysis. To this end, the trace molecules can be concentrated and enriched for surface-enhanced Raman scattering (SERS). In this work, the ZIF-67 was Ni 2 + -acid etched into Co–Ni layered double hydroxide (LDH) hollow nanocages. After introducing Au nanoparticles (NPs), Au NPs@Co–Ni LDH core–shell structured composites with a very low detection limit for RhB (10 –10 mol L −1 ) were formed. The composites were applied to non-extra-artificial destructive detection of green, red, and blue trace mural mineral pigments, in which the main components were identified as chlorocopperite, vermilion and ultramarine, respectively. This result proves the universality of the composites to mural pigments of different types in different regions. Experimental data and finite element simulation results show that the etching treatment endowed the SERS substrate materials with a concentration effect, which led to more molecules of the substances to be measured aggregating around the Au NPs, enhanced the detection signals of the molecules, and achieved the concentration in the plasmonic field, which in turn improved their adsorption capacity and enrichment function of the target molecules. This work realizes the innovative application of the concentration effect in the SERS detection of ancient mural pigments, which is important for the analysis, identification, and restoration of mural paintings and other cultural relics.
Non-steroidal anti-inflammatory drugs (NSAIDs) have gained significant attention as emerging pollutants and are increasingly detected in aquatic environments. Therefore, it is imperative to investigate the efficient removal of NSAIDs from water systems. In this study, a magnetic LDH with three-dimensional hollow structure (Fe 3 O 4 @ZIF-67@Co-Ni LDH) was synthesized using ZIF-67 as a template for the removal of carprofen (CPF) and flurbiprofen (FLU) from water environments. The adsorption process of CPF and FLU on Fe 3 O 4 @ZIF-67@Co-Ni LDH and the competitive adsorption between these two NSAIDs were investigated. The adsorption mechanism was explored by experimental analysis and theoretical calculation. Results demonstrated that the pseudo-second-order kinetic model and Liu isotherm model can better fit the kinetic and isotherm data, and according to the thermodynamic data analysis, the adsorption process was exothermic, spontaneous and stable. The adsorption capacity of CPF and FLU on Fe 3 O 4 @ZIF-67@Co-Ni LDH can reach 856.2 mg/g and 797.5 mg/g. Fe 3 O 4 @ZIF-67@Co-Ni LDH exhibited high adsorption capacity for CPF and FLU in actual environment water, with stronger affinity towards CPF when both NSAIDs coexisted simultaneously. The three-dimensional hollow structure enhanced the adsorption capacity of Fe 3 O 4 @ZIF-67@Co-Ni LDH, making it a promising adsorbent for NSAIDs.
A novel unique adsorbent (Fe 3 O 4 @Co/Ni-LDH) has been successfully synthesized and applied for removal of bisphenols (BPs) from aqueous solution. The prepared adsorbent was characterized to appear in a hierarchical rattle-like structure, and possesses high specific surface area, abundant pore system, and magnetic properties. Adsorption kinetics fitted well with the pseudo-second-order model. Adsorption isotherms abide by the Langmuir model, and the maximum adsorption capacity for bisphenol A (BPA), F (BPF), AF (BPAF) and S (BPS) on Fe 3 O 4 @Co/Ni-LDH at pH of 7.0 were 238.96, 177.09, 320.56 and 345.84 mg/g, respectively. Moreover, it was found that the high pH and NaCl concentration were not conducive to the removal of BPs. The humic acid and real waters had no significant effects on the removal of BPs on Fe 3 O 4 @Co/Ni-LDH. Furthermore, the FT-IR spectra indicated that the removal of four BPs were primarily Hydrogen bond interaction between BPs and Fe 3 O 4 @Co/Ni-LDH. The Fe 3 O 4 @Co/Ni-LDH was regenerated effectively by methanol and can be repeatedly used. This novel Fe 3 O 4 @Co/Ni-LDH can be applied as a promising adsorbent for removal of BPs from aqueous matrices.
危险品化学品经营许可证（带存储）