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Heteroatom doping plays a crucial role in improving the electrocatalytic performance of catalysts towards water splitting. Owing to the existence of Ru-O moieties, Ru is thus emerging as an ideal dopant for promoting the electrocatalytic performance for water splitting by modifying the electronic structure, introducing extra active sites, improving electronic conductivity, and inducing a strong synergistic effect. Benefitting from these advantages, Ru-doped nanomaterials have been widely investigated and employed as advanced electrocatalysts for water splitting, and many excellent Ru-doped electrocatalysts have been successfully developed. In an effort to obtain a better understanding of the influence of Ru doping on the electrocatalytic water splitting performance of nanocatalysts, we herein summarize the recent progress of Ru-doped electrocatalysts by focusing on the synthesis strategies and advantageous merits. Applications of these new materials in water electrolysis technology are also discussed with emphasis on future directions in this active field of research.

Developing advanced electrocatalysts is of great significance for boosting electrochemical water splitting to produce hydrogen. The electrocatalytic activity of a catalyst is associated with the surface/interface, geometric structure, and electronic properties. Coupling Ir with transition metal compounds is an effective strategy to improve their electrocatalytic performance. In this review, we summarize the recent progress of Ir coupled transition metal compound catalysts for the application in driving electrochemical water splitting. The significant role of Ir played in the promotion of electrocatalytic performance is firstly illustrated. Then, the applications of Ir-based catalysts in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are comprehensively discussed, with an emphasis on correlating the structure-function relationships. Lastly, the challenges and future directions for the fabrication of more advanced Ir coupled electrocatalysts are also presented.

Electrochemical water splitting plays a crucial role in transferring electricity to hydrogen fuel and appropriate electrocatalysts are crucial to satisfy the strict industrial demand. However, the successfully developed non-noble metal catalysts have a small tested range and the current density is usually less than 100 mA cm

Cancer has become one of the main reasons for human death in recent years. Around 18 million new cancer cases and approximately 9.6 million deaths from cancer reported in 2018, and the annual number of cancer cases will have increased to 22 million in the next two decades. These alarming facts have rekindled researchers' attention to develop and apply different approaches for cancer therapy. Unfortunately, most of the applied methods for cancer therapy not only have adverse side effects like toxicity and damage of healthy cells but also have a short lifetime. To this end, introducing innovative and effective methods for cancer therapy is vital and necessary. Among different potential materials, carbon nanomaterials can cope with the rising threats of cancer. Due to unique physicochemical properties of different carbon nanomaterials including carbon, fullerene, carbon dots, graphite, single-walled carbon nanotube and multi-walled carbon nanotubes, they exhibit possibilities to address the drawbacks for cancer therapy. Carbon nanomaterials are prodigious materials due to their ability in drug delivery or remedial of small molecules. Functionalization of carbon nanomaterials can improve the cancer therapy process and decrement the side effects. These exceptional traits make carbon nanomaterials as versatile and prevalent materials for application in cancer therapy. This article spotlights the recent findings in cancer therapy using carbon nanomaterials (2015-till now). Different types of carbon nanomaterials and their utilization in cancer therapy were highlighted. The plausible mechanisms for the action of carbon nanomaterials in cancer therapy were elucidated and the advantages and disadvantages of each material were also illustrated. Finally, the current problems and future challenges for cancer therapy based on carbon nanomaterials were discussed.

Sulfamic acid functionalized PVC-coated nano-silica (NS) catalyst (NS@PVC-EDA-SO3H) was prepared via multi-step treatment processes and characterized by FT-IR, N2 adsorption-desorption, TGA/DTG, XR...

Imidazolyl activated carbon, denoted as AC-N, was prepared via oxidation of AC with HNO3 (AC-O) and then refluxed with ethanediamine under mild conditions. The results showed that the N content of AC-N was 10.3%, and the surface alkali group density of AC-N was 0.96 mmol g−1 from 0.78 mmol g−1 carboxy group of AC-O by Boehm titration. It was revealed that the basic functional groups on the AC-N surface included imidazole and amine groups, from XPS and FT-IR. Evaluated with Michael addition of furfural, the catalytic performance of AC-N showed higher conversion and selectivity than that of commonly used base catalyst such as 2-methylimidazole and KOH. Very remarkably, AC-N showed extraordinary recyclability, in that there was no decline of conversion and selectivity after being recycled 5 times.

Doping is an effective approach to regulate the physicochemical properties of carbon dots (CDs) and has received increasing attention in recent years. After CDs are doped with heteroatoms, their electronic structure, nanostructure, and chemical composition will be changed due to the overlapping atomic orbitals of the heteroatoms and carbon atoms, as well as the push/pull electron effect of heteroatoms. As compared with the non-metallic atoms, metal ions have more electron and unoccupied orbitals, and larger atomic radius, doping CDs with metal ions may induce noticeable alterations of the optical, electronic, and magnetic properties by changing the electron density distribution and energy gap of the CDs. In this review, we summarize the synthesis methods of metal ions-doped CDs (M−CDs), discuss the novel physicochemical properties originating from the doping of metal ions, and provide examples of applications in sensing, imaging, phototherapy, optoelectronics, and catalysis. Furthermore, we describe challenges in preparing M−CDs and provide an outlook for their future development.

Rational design of highly efficient electrocatalysts with favorable electronic and geometric structure toward sluggish oxygen evolution reaction (OER) grasps the key in unlocking the wide application of hydrogen energy through water electrolysis. Herein, an innovative type of ultralow noble metals (Ir and Ru) doped hollow Ni(OH)2 nanocage electrocatalysts are successfully constructed through an ion-assisted etching protocol. Interestingly, a remarkable OER activity is achieved for Ir-Ni(OH)2 nanocage, delivering a current density of 10 mA cm−2 with an ultralow overpotential of 248 mV in 1 M KOH electrolyte. More importantly, this synthetic method can also be extended to the synthesis of Ru-Ni(OH)2 nanocages with outstanding OER performance. Mechanism study reveals that the superior OER performance is attributed to the ultralow noble metal doping, which not only effectively modifies the electronic structure of Ni(OH)2, but also functions as the active sites toward OER. Moreover, the highly open hollow nanocage structure enables the catalyst to provide more exposed active sites available for reaction intermediates, contributing to the outstanding OER performance.

A series of Fe 2 O 3 doped SBA-15 materials were prepared via an equivalent-volume impregnation method. The resultant Fe 2 O 3 -containing SBA-15 materials showed good performance in phenol methylation. Under the same conditions, the mesoporous catalyst with 5 wt.% Fe 2 O 3 showed the superior catalytic activity to that of pristine α -Fe 2 O 3 even at lower reaction temperature (320 °C vs. 350 °C). The elevated catalytic activity observed for the mesoporous catalyst could be due to high level dispersion of Fe 2 O 3 species in the mesoporous framework. Furthermore, the mesoporous catalyst possessed long lifetimes, which could be used continuously for 2000 h without significant loss of activity.

Carbon dots (CDs) are novel zero-dimensional carbonaceous nanomaterial, and they are featured with an attractive combination of physical, chemical, and biomedical properties including wide absorption spectrum, tunable fluorescence, excellent water solubility, outstanding photostability, and biocompatibility, which leads to their diverse applications as optically functional materials in various fields, e.g., fluorescence sensing, bioimaging, and drug delivery. Recently, it was revealed that CDs could be used as an effective photosensitizer to generate reactive oxygen species under light excitation, and/or a photothermal agent to convert light energy into heat, which enable them to be applied in photodynamic therapy or photothermal therapy for cancer treatment. In this review, we summarize the latest progress of research on CDs in phototherapy, including their use as nanocarriers for organic phototherapy agents, and highlight the strategies which are adopted to improve the therapeutic efficacy of CDs-based phototheranostics. Furthermore, we also discuss the challenges and prospects of the CDs-based phototheranostics towards clinical applications. We hope this review will provide critical insights to inspire new exciting discoveries on CDs from both fundamental and practical views so as to prompt their advances in the phototherapy.

A novel α-Fe 2 O 3 catalyst for the ortho-methylation of phenol with methanol was synthesized by a combination of co-precipitation and microwave drying technologies. The resultant catalyst was characterized by XRD, BET surface area, XPS, TEM, TG-DTG, and NH 3 -TPD. As compared with air oven dried α-Fe 2 O 3 catalyst, the microwave dried one demonstrated larger specific surface area, bigger pore volume, as well as more acidity, and hence exhibited superior catalytic property for the ortho-methylation of phenol with methanol. Under the reaction conditions of 623 K, WHSV 0.8 h −1 , and n(phenol):n(methanol):n(water) = 1:2:0.5, the conversion of phenol on microwave dried α-Fe 2 O 3 was 67.0%, 21 percentage points higher than that of oven dried catalyst, the selectivity of o -cresol was 88.5%, and total ortho-selectivity of o -cresol and 2,6-xylenol was nearly constant as 99.7%, that is, almost all methyl group in methanol was guided to ortho-C site of OH group in phenol. The microwave dried α-Fe 2 O 3 catalyst could be synthesized with good repeatability, and conveniently reactivated. The catalyst still remained high catalytic activity after continuous 2000 h operation at the temperature from 623 K to 653 K.

Amino modified SBA-15 (SBA-NH2) was used to immobilize vanadyl (VO2+) and cupric (Cu2+) ions, giving SBA-NH2-VO2+ and SBA-NH2-Cu2+ catalysts, respectively, and the as-prepared catalysts were characterized by XRD, XPS, TEM and Nitrogen adsorption–desorption technologies. The catalytic performance of the SBA-NH2-VO2+ catalysts for the oxidation of HMF can be enhanced by the use of SBA-NH2-Cu2+ as the co-catalyst. Several important reaction parameters were investigated, and it was found that the reaction solvent showed a great effect on the oxidation of HMF. The highest HMF conversion and product selectivity were obtained in aromatic solvents. The highest HMF conversion reached 98.8% at 110 °C in 4-chlorotoluene, affording DFF and 2,5-furandicarboxylic acid (FDCA) with yields of 28.9% and 62.7%, respectively. More importantly, the catalysts could be recycled and showed no significant decrease of their catalytic activities.

Several C1–C4 alkylammonium hydrosulfates [R3NH][HSO4] have been conveniently prepared from the cheap raw materials sulfuric acid and alkylamines. Their acidities were measured by chemical titration and determined using UV-vis spectroscopy with a basic indicator 4-nitroaniline. The catalytic performance of these hydrosulfates for the condensation of phenol with formaldehyde to bisphenol F (BPF) was evaluated in detail on a batch reactor. The results indicated that the proposed catalysts are very active for such condensation due to its homogeneous catalysis characteristics in reaction conditions. Among the catalysts examined, [H3NCH2CH2NH3][HSO4]2 shows the best catalytic performance and it can achieve a complete conversion of formaldehyde, providing a higher than 90% selectivity for BPF under the optimal conditions. Furthermore, the catalyst can be recovered from the reaction mixture via an azeotropic distillation with cyclohexane to remove water and then filtration and used repeatedly six times almost without loss of activity, showing an excellent reusability. It is suggested that the present catalytic process combines the characteristics of a homogenized reaction and heterogenized recovery so might provide a highly-efficient, environmentally-friendly and low-cost route for synthesis of bisphenol F.

A new manganese-containing hollow framework TS-1 (MTS-1) was prepared via simple recrystallization of traditional TS-1 in the presence of tetrapropylammonium hydroxide (TPAOH) and manganese(III)–acetylacetonate, and its catalytic performance was tested for aerobic oxidation of cyclohexene without any solvents. This hollow bimetal TS-1 catalyst is more active than catalysts containing Mn or Ti solely; the formation of metal framework sites may be responsible for increased activity. The characterization techniques such as UV-vis, FT-IR, Raman, XRD, N2-adsorption, TEM, and XPS confirm the incorporation of Mn and Ti in the zeolite framework sites. This hollow catalyst shows high catalytic activity and stability (ten cycles) in the oxidation of cyclohexene, and demonstrates the potential of TS-1 catalysts for use in aerobic oxidations.

S,N-doped carbon dots (S,N-CDs) were facilely prepared via a hydrothermal method by using thiourea and citric acid (CA) as precursors. The as-prepared S,N-CDs exhibited high stability in aqueous solution and were applied for fluorometric detection of tetracyclines (TCs). The approach was developed on the basic of the fluorescence of S,N-CDs at 440 nm, which was selectively quenched by TCs through the inner filter effect (IFE) mechanism. Moreover, the fluorescence of TCs with maximum at 600 nm could be used as the internal standard signal, resulting in a fluorometric spectral response. The limit of detection (LOD) was 0.25, 0.39 and 0.26 μM for tetracycline (TC), doxycycline (DC) and oxytetracycline (OTC), respectively. Furthermore, S,N-CDs were successfully utilized for the detection of residual TCs in fish and pork samples with acceptable recovery and good RSD.

Dimethyl toluene-2,4-dicarbamate (2,4-TDC) was selected as a model compound for aromatic polyurethane to investigate the photo-chemical behavior of commercial TiO2 pigments in non-aqueous solution. The UV–Visible spectrometry analysis results showed that the UV-shielding ability of the rutile TiO2 pigment was better than that of the anatase TiO2 pigment. Photodegradation experiments suggested that the photodegradation of 2,4-TDC was retarded by rutile TiO2 pigment, while accelerated by anatase TiO2 pigment. With the help of the degradation intermediates during the photodegradation process and calculated data, such as point charges and bond length, the preliminary photodegradation mechanism of 2,4-TDC was also briefly elucidated, including the addition of hydroxyl radicals and the cleavage of the carbamate side chain. Additionally, the photodegradation of 2,4-TDC was used to evaluate the photoreactivity of TiO2 pigments, this is proved to an efficient approach with potential application in industry.

One-step oxidation of cyclohexane to adipic acid (AA) was carried out at 413 K over manganese-doped titanium silicalite with hollow structure (HTS) using oxygen as oxidant without any initiator or solvent. The catalyst exhibited high conversion (13.4%) and reasonable product (AA) selectivity (57.5%). Hot-separation and catalyst-recycle tests proved that the catalyst acted as a heterogeneous one and it could be reused four times without losing its activity. The synthesized materials were characterized by N2 adsorption–desorption isotherm, FT-IR, UV–vis and XPS techniques.

A novel hollow-structured Mn/TS-1 catalyst has been reported as a non-nitric acid route for adipic acid production from oxidative cleavage of cyclohexanone. The method generates adipic acid in high yields with molecular oxygen under organic solvent- and promoter-free conditions. The hollow nature of the catalyst with large intra-particle voids facilitates the diffusion of bulky molecules to the internal catalytic site and increases the catalyst activity. The advantage of this catalyst is its reusability with almost consistent reactivity, thereby making it viable for industrial applications.