Jiabin Cui

Near-Infrared Plasmonic-Enhanced Solar Energy Harvest for Highly Efficient Photocatalytic Reactions

We report a highly efficient photocatalyst comprised of Cu7S4@Pd heteronanostructures with plasmonic absorption in the near-infrared (NIR)-range. Our results indicated that the strong NIR plasmonic absorption of Cu7S4@Pd facilitated hot carrier transfer from Cu7S4 to Pd, which subsequently promoted the catalytic reactions on Pd metallic surface. We confirmed such enhancement mechanism could effectively boost the sunlight utilization in a wide range of photocatalytic reactions, including the Suzuki coupling reaction, hydrogenation of nitrobenzene, and oxidation of benzyl alcohol. Even under irradiation at 1500 nm with low power density (0.45 W/cm(2)), these heteronanostructures demonstrated excellent catalytic activities. Under solar illumination with power density as low as 40 mW/cm(2), nearly 80-100% of conversion was achieved within 2 h for all three types of organic reactions. Furthermore, recycling experiments showed the Cu7S4@Pd were stable and could retain their structures and high activity after five cycles. The reported synthetic protocol can be easily extended to other Cu7S4@M (M = Pt, Ag, Au) catalysts, offering a new solution to design and fabricate highly effective photocatalysts with broad material choices for efficient conversion of solar energy to chemical energy in an environmentally friendly manner.

Ultrasmall Cu7S4@MoS2 Hetero‐Nanoframes with Abundant Active Edge Sites for Ultrahigh‐Performance Hydrogen Evolution

Increasing the active edge sites of molybdenum disulfide (MoS2 ) is an efficient strategy to improve the overall activity of MoS2 for the hydrogen-evolution reaction (HER). Herein, we report a strategy to synthesize the ultrasmall donut-shaped Cu7 S4 @MoS2 hetero-nanoframes with abundant active MoS2 edge sites as alternatives to platinum (Pt) as efficient HER electrocatalysts. These nanoframes demonstrate an ultrahigh activity with 200 mA cm(-2) current density at only 206 mV overpotential using a carbon-rod counter electrode. The finding may provide guidelines for the design and synthesis of efficient and non-precious chalcogenide nanoframe catalysts.

Cu7S4 Nanosuperlattices with Greatly Enhanced Photothermal Efficiency

According to the simulation, the self-assembly of Cu7 S4 nanocrystals would enhance the photothermal conversion efficiency (PCE) because of the localized surface plasmon resonance effects, which is highly desirable for photothermal therapy (PTT). A new strategy to synthesize Cu7 S4 nanosuperlattices with greatly enhanced PCE up to 65.7% under irradiation of 808 nm near infrared light is reported here. By tuning the surface properties of Cu7 S4 nanocrystals during the synthesis via thermolysis of a new single precursor, dispersed nanoparticles (NPs), rod-like alignments, and nanosuperlattices are obtained, respectively. To explore their PTT applications, these hydrophobic nanostructures are transferred into water by coating with home-made amphiphilic polymer while maintaining their original structures. Under identical conditions, the PCE are 48.62% and 56.32% for dispersed NPs and rod-like alignments, respectively. As expected, when the nanoparticles are self-assembled into nanosuperlattices, the PCE is greatly enhanced up to 65.7%. This strong PCE, along with their excellent photothermal stability and good biocompatibility, renders these nanosuperlattices good candidates as PTT agents. In vitro photothermal ablation performances have undoubtedly proved the excellent PCE of our Cu7 S4 nanosuperlattices. This research offers a versatile and effective solution to get PTT agents with high photothermal efficiency.

Down-/up-conversion luminescence nanocomposites for dual-modal cell imaging

Dual-modal luminescence nanocomposites (NCs) were successfully prepared via a facile and versatile strategy by embedding the hydrophobic down-conversion (DC) fluorescence ZnS:Mn2+ quantum dots (QDs) and up-conversion (UC) luminescence NaYF4:Er3+/Yb3+ nanoparticles (NPs) into hydrophilic polymer matrixes through in situ cross-linking polymerization. Due to the enriched carboxylic groups in the polymer matrixes, the as-prepared NCs are highly water-stable and bioconjugatable with chemical and biological moieties. The results of cytotoxicity assay and dual-modal luminescence cell imaging application of DC-UC NCs indicate that the as-prepared NCs are biocompatible and applicable in biomedical fields. The current work paves the way to the fabrication of multifunctional NCs including down- and up-conversion dual-modal luminescence, luminescence-magnetism, magnetic targeted drug vehicles and magnetic recyclable catalyst NCs, and will attract wide attention from the fields of chemistry, materials, catalysis, nanotechnology, nanobiotechnology and nanomedicine.

Smart Cu1.75S nanocapsules with high and stable photothermal efficiency for NIR photo-triggered drug release

Thermosensitive drug delivery systems (DDSs) face major challenges, such as remote and repeatable control of in vivo temperature, although these can increase the therapeutic efficacy of drugs. To address this issue, we coated near-infrared (NIR) photothermal Cu1.75S nanocrystals with pH/thermos-sensitive polymer by in situ polymerization. The doxorubicine (DOX) loading content was up to 40 wt.%, with less than 8.2 wt.% of DOX being leaked under normal physiological conditions (pH = 7.4, 37 °C) for almost 48 h in the absence of NIR light. These nanocapsules demonstrate excellent photothermal stability by continuous longterm NIR irradiation. Based on the stable and high photothermal efficiency (55.8%), pre-loaded drugs were released as desired using 808-nm light as a trigger. Both in vitro and in vivo antitumor therapy results demonstrated that this smart nanoplatform is an effective agent for synergistic hyperthermia-based chemotherapy of cancer, demonstrating remote and noninvasive control.

Highly Efficient Photothermal Semiconductor Nanocomposites for Photothermal Imaging of Latent Fingerprints

Optical imaging of latent fingerprints (LFPs) has been widely used in forensic science and for antiterrorist applications, but it suffers from interference from autofluorescence and the substrates background color. Cu7S4 nanoparticles (NPs), with excellent photothermal properties, were synthesized using a new strategy and then fabricated into amphiphilic nanocomposites (NCs) via polymerization of allyl mercaptan coated on Cu7S4 NPs to offer good affinities toward LFPs. Here, we develop a facile and versatile photothermal LFP imaging method based on the high photothermal conversion efficiency (52.92%, 808 nm) of Cu7S4 NCs, indicating its effectiveness for imaging LFPs left on different substrates (with various background colors), which will be extremely useful for crime scene investigations. Furthermore, by fabricating Cu7S4-CdSe@ZnS NCs, a fluorescent-photothermal dual-mode imaging strategy was used to detect trinitrotoluene (TNT) in LFPs while still maintaining a complete photothermal image of LFP.

Development of NIR-II fluorescence image-guided and pH-responsive nanocapsules for cocktail drug delivery

Nanocapsule-based targeted delivery and stimulus-responsive release can increase drug effectiveness, while reducing the side effects of the drug. However, difficulties in the scale-up synthesis, fast burst release, and low degradability, could hamper the translation of drug nanocapsules from lab to clinic. Here we have controllably functionalized the biodegradable and widely available polysuccinimide, in order to obtain an amphiphilic poly(amino acid). Using this polymer, we designed nanocapsules (< 100 nm) for hydrophobic drug delivery, which could facilitate tumor targeting, hydrogen bond-based pH-responsive release, and real-time fluorescence tracking, in the second near-infrared region. This method is versatile, eco-friendly, and easy to scale up at low costs. In addition, this system can carry a cocktail of drugs, obtained by loading multiple anticancer drugs to the same vehicle. Our nanocapsules were observed to be stable in blood vessels (pH = 7.4), and the pH-responsive release (pH = 5.0 in lysosome) was sustained. The chemotherapy results in tumor-xenografted mice suggested that our nanocapsule was safe and efficient, and may be a useful tool for drug delivery.

Plasmon-Enhanced Photoelectrical Hydrogen Evolution on Monolayer MoS2 Decorated Cu1.75S-Au Nanocrystals

Hydrogen production from water splitting through an efficient photoelectrochemical route requires photoinduced electron transfer from light harvesters to efficient electrocatalysts. Here, the plasmon-enhanced photoelectrical nanocatalysts (NCs) have been successfully developed by coating a monolayer MoS2 on the Cu1.75 S-Au hetero-nanoparticle for hydrogen evolution reaction (HER). The plasmonic NCs dramatically improve the HER, leading to 29.5-fold increase of current under 650 nm excitation (1.0 W cm-2 ). These NCs generate an exceptionally high current density of 200 mA cm-2 at overpotential of 182.8 mV with a Tafel slope of 39 mV per decade and excellent stability, which is better than or comparable to the Pt-free catalysts with carbon rod as counter electrode. The enhanced HER performance can be attributed to the significantly improved broad light absorption (400-3000 nm), more efficient charge separation and abundant active edge sites of monolayer MoS2 . The studies may provide a facile strategy for the fabrication of efficient plasmon-enhanced photoelectrical NCs for HER.

Highly efficient PdCu3 nanocatalysts for Suzuki–Miyaura reaction

Suzuki–Miyaura reactions, involving the activation of carbon–halogen bonds, especially C–Cl bonds, have drawn widespread attention because of their huge industrial potential. However, these reactions are dependent on the development of highly active and stable catalysts. Herein, we developed a convenient one-pot wet route to synthesize PdxCuy bimetallic nanocrystals for the Suzuki–Miyaura reaction. By introducing Cu, an earth-abundant element, the catalytic activity was greatly enhanced while the amount of Pd required was reduced. PdxCuy nanocrystals of different compositions, including Pd3Cu, Pd2Cu, PdCu, PdCu2, and PdCu3, were successfully synthesized by tuning the Pd:Cu ratio. Their catalytic performance in Suzuki–Miyaura reactions between phenylboronic acid and halobenzenes (iodo-, bromo-, or chlorobenzene) showed that PdCu3 nanocatalyst demonstrated the best efficacy.

Monolayer MoS 2 decorated Cu 7 S 4 -Au nanocatalysts for sensitive and selective detection of mercury(II)

Sensitive and selective detection of Hg(II) contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 (S-MoS2) decorated Cu7S4-Au (Cu7S4-Au@S-MoS2) nanocomposite modified electrode for the sensitive and selective detection of Hg(II) via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of smallmonolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity (LOD = 190 nmol L−1) and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 (M: multilayer) were also investigated, but showed low response to Hg(II), suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg(II). Moreover, the developed method displays satisfied performance for the detection of Hg(II) in real samples, which indicates its potentials in practical applications.摘要汞的灵敏选择性检测对于人类的公共安全至关重要. 本文成功制备了单层二硫化钼修饰的Cu7S4-Au纳米结构(Cu7S4-Au@S-MoS2), 通过阳极溶出伏安法实现了对汞的灵敏选择性分析检测. 基于超小(<10 nm)单层MoS2丰富的活性位点及金对汞的良好亲和性, 该方法灵 敏度高(检出限为190 nmol L−1)、选择性好(常见Cd2+、Pb2+、Cu2+等均无干扰), 并成功用于实际样品中汞的灵敏分析. 研究发现Cu7S4-Au与 Cu7S4@S-MoS2 对Hg(II) (1.0 μmol L−1)无响应, 而多层MoS2修饰的Cu7S4-Au(Cu7S4-Au@M-MoS2)对Hg(II) (1.0 μmol L−1) 有弱响应, 结果表明 超小单层MoS2丰富的活性位点及金对汞的良好亲和性对分析检测起到了协同催化作用.