Three dibenzothiophene-S,S-dioxide-based alternating copolymers were synthesized by facile Suzuki polymerization for visible light-responsive hydrogen production from water (> 420 nm). Without addition of any cocatalyst, FluPh2-SO showed a photocatalytic efficiency of 3.48 mmol h g- , while a larger hydrogen evolution rate (HER) of 4.74 mmol h g was achieved for Py-SO, which was ascribed to the improved coplanarity of the polymer that facilitated both intermolecular packing and charge transport. To minimize the possible steric hindrance of FluPh2-SO by replacing 9,9'-diphenylfluorene with fluorene, Flu-SO exhibited a more red-shifted absorption than FluPh2-SO and yielded the highest HER of 5.04 mmol h g . This work highlights the potential of dibenzothiophene-S,S-dioxide as a versatile building block and the rational design strategy for achieving high photocatalytic efficiency.
Graphene, including pristine graphene and its analogues of graphene oxide and reduced graphene oxide, is revolutionizing the way we design high performance devices, particularly in the areas of sustainable energy and environmental technologies. From environmental remediation and sensing to energy conversions and storage, there are many successful cases of graphene applications. Instead of being a standalone working material, graphene is almost always coupled with another active material as a composite. With its high surfaceto-bulk ratio, efficient heat transfer, and electron conduction, the interfacing with graphene not only helps to overcome such limitations in the bare working material but actually accentuates them. To achieve this, the strategy of surface functionalization of graphene, with either soft matters (e.g., organics, molecular linkers, proteins) or solid inorganic matters (e.g., metal nanoparticles, oxide semiconductors), holds the key to enabling the fabrication of high performance composites. The resultant architectures, in which the graphene is applied to, yield the highest achievable properties and should be unique to the specific applications. This Review provides a bottom-up account encompassing the functionalization of graphene to the design of graphene-based composites and also their selected applications in high performance systems relevant to energy and the environment.
Titanium dioxide (TiO2) has been densely investigated owing to its low cost, benign nature and strong photocatalytic ability. Thus, TiO2 has broad applications including photocatalysts, Li-ion batteries, solar cells, medical...
Two novel triphenylamine based conjugated microporous polymers are designed and synthesized for photocatalytic CO2 reduction using water vapor as electron donor under ambient condition (>420 nm).
Facile functionalization of graphene oxide sheets on gold surface results in complexation-enhanced electrochemical detection of heavy metal ions, shown here for Pb2+, Cu2+ and Hg2+, with improved detection limits by two orders of magnitude relative to the control electrode.
Covalently grafting pyrene groups on polymeric carbon nitride enables photocatalytic CO2 reduction in aqueous solution with simultaneous alkene oxidation in organic phase.
Composite
photoelectrodes consisting of CdS sensitizer, reduced
graphene oxide (rGO) transporter, and TiO2 acceptor were
synthesized in a solvothermal synthesis. Under solvothermal conditions,
the dimethyl sulfoxide (DMSO) solvent medium decomposed to form free
sulfides, which facilitated the formation of CdS and, at the same
time, which also reduced graphene oxide sheets by forming disulfide
moieties. Compared to pure CdS and TiO2, coupling of these
materials either as bi- or tricomponent composites (including rGO)
allowed efficient interfacial charge separation and prolonged electron
lifetimes. In particular, in the CdS/rGO/TiO2 tricomposite
case, the rGO plays vital roles in alleviating trapped electrons at
the heterojunction and serves as a platform for shuttling electrons
between CdS and TiO2. Taking into account all of the structure-related
charge-transport characteristics, including interfacial contacts,
the highest quantum efficiency (incident photon-to-current efficiency,
IPCE, at 460 nm = 12%) was achieved for the CdS/rGO/TiO2 tricomposite, and this was 6-fold that of CdS/TiO2.
The supercapacitor has been widely seen as one of the most promising emerging energy storage devices, by which electricity is converted from chemical energy and stored. Two-dimensional (2D) metal oxides/hydroxides (TMOs/TMHs) are revolutionizing the design of high-performance supercapacitors because of their high theoretical specific capacitance, abundance of electrochemically active sites, and feasibility for assembly in hierarchical structures by integrating with graphitic carbon, conductive polymers, and so on. The hierarchical structures achieved can not only overcome the limitations of using a single material but also bring new breakthroughs in performance. In this article, the research progress on 2D TMOs/TMHs and their use in hierarchical structures as supercapacitor materials are reviewed, including the evolution of supercapacitor materials, the configurations of hierarchical structures, the electrical properties regulated, and the existence of advantages and drawbacks. Finally, a perspective covering directions and challenges related to the development of supercapacitor materials is provided.
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