Extracting
gold from wastes of electronic equipment (e-waste) is
a sustainable strategy for the recovery of the precious metal, reducing
environmental pollution, and addressing the growing demands for gold
resources. In this work, we synthesized a thiourea-modified porous
aromatic framework (PAF-1-thiourea) with exceptional gold-extraction
ability. The optimum adsorption capacity for PAF-1-thiourea to gold
reaches up to 2629.87 mg g–1. The adsorption process
can be well fitted according to the pseudo-second-order kinetic model
and Langmuir model, featuring strong affinity caused by strong soft–soft
interactions between Au(III) and the S and N donor atoms of the modified
PAF and the electrostatic interactions between protonated amino groups
and AuCl4
–. PAF-1-thiourea was especially
capable of extracting gold rapidly and efficiently (capturing 98.73%
of gold within 5 min) from a central processing unit (CPU) in extremely
acidic conditions. It is found that PAF-1-thiourea captures gold ions
and simultaneously converts it to a Au(0) solid, obtaining gold with
purity up to 23.5 karat. PAF-1-thiourea with its high acid resistance
and anti-interference against cheap metals in the recovery process
presents a practical means to extract gold from e-waste.
This review highlights the currently exploited working concepts of lab-on-a-molecule probes, with a particular focus on what is required for multianalyte detection and quantification in competitive assays. Both, chemosensor and chemodosimeter approaches are considered. The multifaceted design strategies and the orthogonal protocols are evaluated in order to identify and categorise the successful conceptions and to single out unknown territory and challenges for future work.
HIGHLIGHTS• A one-pot method was developed for the preparation of fluorescent mesoporous silica nanoparticles-carbon dots (MSNs-CDs) nanohybrid.• The MSNs-CDs nanohybrid showed stable and bright yellow emission, excellent biocompatibility, and specific targeting capability toward folate receptor-overexpressing cancer cells and can be applied as fluorescence imaging-guided drug carriers for effectively delivering anticancer drugs to tumor sites.ABSTRACT Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment. In this work, a novel method for the preparation of a fluorescent mesoporous silica-carbon dot nanohybrid was developed. Carbon dots (CDs), from folic acid as the raw material, were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles (MSNs-NH 2 ) via a microwave-assisted solvothermal reaction. The as-prepared nanohybrid (designated MSNs-CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs (e.g., mesoporous structure, large specific surface area, and good biocompatibility), demonstrating a potential capability for fluorescence imagingguided drug delivery. More interestingly, the MSNs-CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells (e.g., HeLa), indicating that folic acid still retained its function even after undergoing the solvothermal reaction. Benefited by these excellent properties, the fluorescent MSNs-CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted delivery MSNs-CDs@DOX Cancer cell targeted delivery Endocytosis DOX release FL imaging Enhanced chemotherapy FA receptor Cytoplasm N u c le u s pH of anticancer drugs (e.g., doxorubicin), thereby enhancing chemotherapeutic efficacy and reducing side effects. Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms, which is beneficial in the diagnosis and therapy of cancers in future.
Setting up spatially separated HOMO and LUMO regions in a non-Kekulé structured trinuclear Ir(III)-Ru(II)-Ir(III) system and using oxidative-reduction electrochemiluminescence leads to emissions that are not detected in photoluminescence. Moreover, the new design allows tuning of the wavelength of emission in a stepless fashion as a function of the selected potential range.
Inorganic lead halide perovskite quantum dots (iLHP-QDs)
have recently been used in the photocatalytic reaction. However, the
factors that influence the photocatalytic performance of the iLHP-QDs
have not been fully investigated. Herein, we synthesized a series
of iLHP-QDs with varied halide ratios (CsPbX3, X = I, I0.67Br0.33, I0.5Br0.5, I0.33Br0.67, Br) and studied their influence on the
photocatalytic performance by monitoring the polymerization of 2,2′,5′,2″-ter-3,4-ethylenedioxythiophene
(TerEDOT). The CsPbI3 QDs showed the best performance owing
to their narrow band gap and low exciton binding energy. Moreover,
the photocatalytic performance of the iLHP-QDs could be simply improved
by being treated with methyl acetate, which can be attributed to the
replacement of the oleic acid by the short acetate acid and the introduction
of the traps on the surface of QDs in the post-treatment. These results
could help design a more efficient photocatalytic system and further
promote the application of iLHP-QDs.
Thermal decomposition study of dihydroxylammonium 5,5 0 -bistetrazole-1,1 0 -diolate (TKX-50) was investigated by using TG-DTG and TG-IR-MS and found that N 2 , N 2 O, NH 3 and H 2 O were the main products during the decomposition process. The kinetic parameters (Ea = 138.96 kJ mol -1 and A = 10 12.93 s -1 ) for thermal decomposition reaction of TKX-50 were obtained from DSC profile by differential method and integral method, and the nonisothermal kinetic equation of the exothermic process was da=dT ¼ ð10 12:93 =bÞ3ð1 À aÞ½À lnð1 À aÞ 2=3 expðÀ1:6713  10 4 =TÞ; suggesting that the main exothermic decomposition reaction mechanism of TKX-50 was classified as Avrami-Erofeev equation. In addition, the theoretical detonation velocity (D = 8804 m/s) of TKX-50 at 298.15 K was calculated by a simple method. Finally, the safety parameters of TKX-50 (25 kg) including time to maximum rate under adiabatic conditions and self-accelerating decomposition temperature were calculated to be 142.12 and 129.01°C by using AKTS software.
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