Photoluminescence Properties of CdSe/ZnS Quantum Dot Donor-Acceptor via Plasmon Coupling of Metal Nanostructures and Application on Photovoltaic Devices.

Hybrid nanostructures composed of quantum dots (QDs) and metal nanoparticles (MNS) have gained immense research interest because of their unique optical properties. In optoelectronic applications, quenching and enhancement in QD photoluminescence (PL) are critical parameters. Herein, gold nanoparticles coating a silica layer decorated with quantum dots (AuNPs@SiO2@QDs) are prepared with diverse SiO2 thickness and QD diameter for investigating the exciton-plasmon interaction. This reveals the charge interaction between QDs and AuNPs@SiO2 resulting from different impacts of the Föster energy-transfer process and plasmon resonance enhancement. The variation in both radiative and nonradiative energy-transfer processes in CdSe/ZnS QDs donor-acceptor pairs clarifies the impact of AuNPs@SiO2. In addition, the hybrid structures are plainly incorporated with silicon solar cells, which activated the improvement in the power conversion efficiency (PCE). With the significant tunability of the PL intensity in the visible and near-infrared regions, this hybrid nanostructure provides potential strategies for developing efficient optoelectronics via facile methods.

Bamboo-like N-doped carbon nanotube-confined cobalt as an efficient and robust catalyst for activating monopersulfate to degrade bisphenol A.

As bisphenol A (BPA) is an extensively used chemical for manufacturing plastic products, discharge of BPA into the environment has caused serious threats to ecology. Therefore, -based chemical oxidation methods have been employed for eliminating BPA. Because monopersulfate (MNP) has become a popular reagent for obtaining , and Co is the most efficient metal for activating MNP, it is critical to develop heterogeneous Co catalysts for easier implementation and recovery. Herein, a unique Co-based catalyst is proposed by utilizing tubular-structured N-doped carbon substrates, derived dicyandiamide (DCDA), to confine Co nanoparticles (NPs). Through simple pyrolysis of a mixture of Co/DCDA, DCDA would be transformed into N-doped carbon nanotubes (CNT) to wrap the resultant Co NP, and, interestingly, this N-doped CNT would exhibit a special bamboo-like morphology. More importantly, as Co NPs are mono-dispersed and singly-confined in N-doped CNTs, forming CoCNT, CoCNT exhibits significantly higher catalytic activities than Co3O4, for activating MNP to degrade BPA. The enhancement of catalytic activities in CoCNT would be possibly ascribed to the synergistic effects between Co NP and the N-doped CNT which not only acts as the support/protection but also provides active sites. Therefore, CoCNT + MNP could lead to a much lower Ea (i.e., 13.8 kJ/mol) of BPA degradation than the reported Ea values. Besides, CoCNT is still effective for eliminating BPA even in the presence of high-concentration NaCl and surfactants. CoCNT is also reusable over many cycles and retains its catalytic activity with 100% BPA removal, demonstrating that CoCNT is an advantageous and robust catalyst for MNP activation.

Metal-complexed covalent organic frameworks derived N-doped carbon nanobubble-embedded cobalt nanoparticle as a magnetic and efficient catalyst for oxone activation.

While Cobalt nanoparticles (Co NPs) are useful for catalytic Oxone activation, it is more advantageous to embed/immobilize Co NPs on nitrogen-doped carbon substrates to provide synergy for enhancing catalytic performance. Herein, this study proposes to fabricate such a composite by utilizing covalent organic frameworks (COF) as a precursor. Through complexation of COF with Co, a stable product of Co-complexed COF (Co-COF) can be synthesized. This Co-COF is further converted through pyrolysis to N-doped carbon in which cobaltic NPs are embedded. Owing to its well-defined structures of Co-COF, the pyrolysis process transforms COF into N-doped carbon with a bubble-like morphology. Such Co NP-embedded N-doped carbon nanobubbles (CoCNB) with pores, magnetism and Co, shall be a promising catalyst. Thus, CoCNB shows a much stronger catalytic activity than commercial Co3O4 NPs to activate Oxone to degrade toxic Amaranth dye (AMD). CoCNB-activated Oxone also achieves a significantly lower Ea value of AMD degradation (i.e., 27.9 kJ/mol) than reported Ea values in previous literatures. Besides, CoCNB is still effective for complete elimination of AMD in the presence of high-concentration NaCl and surfactants, and CoCNB is also reusable over five consecutive cycles.