A review on g-C3N4-based photocatalysts

The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

http://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.5b00482

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

Direct Z-scheme photocatalysts: Principles, synthesis, and applications

The increasing demand of clinical biomedicine and fast development of nanobiotechnology has substantially promoted the generation of a variety of organic/inorganic nanosystems for biomedical applications. Biocompatible two-dimensional (2D) graphene analogues (e.g., nanosheets of transition metal dichalcogenides, transition metal oxides, g-C3N4, Bi2Se3, BN, etc.), which are referred to as 2D-GAs, have emerged as a new unique family of nanomaterials that show unprecedented advantages and superior performances in biomedicine due to their unique compositional, structural and physicochemical features. In this review, we summarize the state-of-the-art progress of this dynamically developed material family with a particular focus on biomedical applications. After the introduction, the second section of the article summarizes a range of synthetic methods for new types of 2D-GAs as well as their surface functionalization. The subsequent section provides a snapshot on the use of these biocompatible 2D-GAs for a broad spectrum of biomedical applications, including therapeutic (photothermal/photodynamic therapy, chemotherapy and synergistic therapy), diagnostic (fluorescent/magnetic resonance/computed tomography/photoacoustic imaging) and theranostic (concurrent diagnostic imaging and therapy) applications, especially on oncology. In addition, we briefly present the biosensing applications of these 2D-GAs for the detection of biomacromolecules and their in vitro/in vivo biosafety evaluations. The last section summarizes some critical unresolved issues, possible challenges/obstacles and also proposes future perspectives related to the rational design and construction of 2D-GAs for biomedical engineering, which are believed to promote their clinical translations for benefiting the personalized medicine and human health.

Two-dimensional graphene analogues for biomedical applications.

Carbon dots: synthesis, formation mechanism, fluorescence origin and sensing applications

Cadmium sulfide (CdS) has long time been one of the most promising inorganic photocatalysts for hydrogen production driven by visible light However, the photocorrosion of CdS is the most serious problem which constrains its development Here, we report the design and fabrication of a carbon dots-cadmium sulfide (CDs-CdS) nanocomposite, showing significant photocatalytic water splitting properties with impressive stability without requirement for any sacrificial agents or cocatalysts The highest hydrogen production rate was obtained for about 255 μmol h −1 , with an oxygen evolution rate for about 052 μmol h −1 , when the concentration of CDs in the sample is 003 g CDs /g catalyst  Even the produced H 2 and O 2 are not equal to the stoichiometric ratio of 2:1 (H 2 :O 2 ), the CDs-CdS nanocomposite shows greater stability (8-time repetitive catalytic experiments) than the CdS catalysts reported up to now (without sacrificial agents or cocatalysts) It is also inspiring that when we increased the concentration of CDs in the catalysts, the produced H 2 and O 2 were gradually adjusted to meet the stoichiometric ratio of 2:1 in spite of low hydrogen production rate (013 μmol h −1 )

Carbon dots enhance the stability of CdS for visible-light-driven overall water splitting

Photocatalytic hydrogen production from overall water splitting is a clean and renewable technology that can convert solar energy into chemical energy, for which developing an efficient and stable photocatalyst has been the central scientific topic. Herein, CoO/g-C3N4 heterojunction photocatalysts were fabricated through a facile solvothermal method for overall water splitting. Simultaneous evolution of H2 and O2 from pure water with the stoichiometric ratio of about 2:1 achieved with all the CoO/g-C3N4 heterojunctions as catalysts under visible light irradiation. Among of them, 30 wt.% CoO/g-C3N4 with H2 evolution rate of 2.51 μmol/h and O2 evolution rate of 1.39 μmol/h also exhibited remarkably higher photocatalytic performance and stability (over 15 cycles) than single CoO or g-C3N4. This enhanced photocatalytic activity of CoO/g-C3N4 heterojunction can be ascribed to the synergistic effect of junction and interface formed between CoO and g-C3N4. In addition, the sufficient long lifetime stability of CoO/g-C3N4 comes from the complementary advantages effect between CoO and g-C3N4, as is proved, CoO can protect g-C3N4 from H2O2 poisoning, and simultaneously the photo-induced heat from CoO during the photocatalytic process responsible for the rapid deactivation can be timely conducted to g-C3N4.

CoO and g-C3N4 complement each other for highly efficient overall water splitting under visible light

Fluorescent N-doped carbon dots for both cellular imaging and highly-sensitive catechol detection

Carbon dots promote the growth and photosynthesis of mung bean sprouts

Self-healing is the way by which nature repairs damage and prolongs the life of bio entities. A variety of practical applications require self-healing materials in general and self-healing polymers in particular. Different (complex) methods provide the rebonding of broken bonds, suppressing crack, or local damage propagation. Here, a simple, versatile, and cost-effective methodology is reported for initiating healing in bulk polymers and self-healing and anticorrosion properties in polymer coatings: introduction of carbon dots (CDs), 5 nm sized carbon nanocrystallites, into the polymer matrix forming a composite. The CDs are blended into polymethacrylate, polyurethane, and other common polymers. The healing/self-healing process is initiated by interfacial bonding (covalent, hydrogen, and van der Waals bonding) between the CDs and the polymer matrix and can be optimized by modifying the functional groups which terminate the CDs. The healing properties of the bulk polymer-CD composites are evaluated by comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that are healed and by following the self-healing of scratches intentionally introduced to polymer-CD composite coatings. The composite coatings not only possess self-healing properties but also have superior anticorrosion properties compared to those of the pure polymer coatings.

Hao Li

Papers

Carbon dots enhance the stability of CdS for visible-light-driven overall water splitting

CoO and g-C3N4 complement each other for highly efficient overall water splitting under visible light

Fluorescent N-doped carbon dots for both cellular imaging and highly-sensitive catechol detection

Carbon dots promote the growth and photosynthesis of mung bean sprouts

Carbon Dots as Fillers Inducing Healing/Self-Healing and Anticorrosion Properties in Polymers