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Solar fuel generation through water splitting and CO 2 photoreduction is an ideal route to provide the renewable energy sources and mitigate global warming. The main challenge in photocatalysis is finding a low-cost photocatalyst that can work efficiently to split water into hydrogen and reduce CO 2 to hydrocarbon fuels. Metal-free g-C 3 N 4 photocatalyst shows great potentials for solar fuel production. In this mini review, we summarize the most current advances on novel design idea and new synthesis strategy for g-C 3 N 4 preparation, insightful ideas on extending optical absorption of pristine g-C 3 N 4 , overall water splitting and CO 2 photoreduction over g-C 3 N 4 based systems. The research challenges and perspectives on g-C 3 N 4 based photocatalysts were also suggested. [ABSTRACT FROM AUTHOR]

Effect of droplet size on wetting behavior on laser textured SiC surface was studied in this work. The micro-square-convex surface was processed on smooth surface with intrisinc contact angle 101°. Then contact angles were measured on both smooth and textured surface by sessile drop method using deionized water with different droplet volume. It was found that there was significant droplet size effect on wetting behaviors for the textured SiC surface. Contact angles on smooth surface kept stable for different water droplet volume with a variation amplitude 13°. However, contact angles increased significantly from 42.25° to 131.25° with increasing droplet volume from 0.001 μL to 1 μL, then remained unchanged when the droplet volume exceeds 1 μL. The correlation analysis shows that contact angles increase with the increasing ratio of base diameter and groove width, then keep stable when the ratio exceeds 25, which explains the wetting behavior for different droplet volume. [ABSTRACT FROM AUTHOR]

A novel composite structure of reduced graphene oxide (rGO)–Ag nanoparticles (Ag NPs) nanocomposite, which was integrated on the indium tin oxide (ITO) glass by a facile and rapid two-step chronoamperometry electrodeposition route, was proposed and developed in this paper. SERS-activity of the rGO/Ag NPs nanocomposite was mainly affected by the structure and size of the fabricated rGO/Ag NPs nanocomposite. In the experiments, the operational conditions of electrodeposition process were studied in details. The electrodeposited time was the important controllable factor, which decided the particle size and surface coverage of the deposited Ag NPs on ITO glass. Under the optimized conditions, the detection limit for rhodamine6G (R6G) was as low as 10 −11 M and the Raman enhancement factor was as large as 5.9 × 10 8 , which was 24 times higher than that for the ITO–Ag NPs substrate. Apart from this higher enhancement effect, it was also illustrated that extremely good uniformity and reproducibility with low standard deviation could be obtained by the prepared ITO-rGO/Ag NPs nanocomposite for SRES detection. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ synthesis N doped CNTs coupled with tunable surface state and constitution of carbon layers. • Co@N-CNTs provides optimal surface for Pt deposition with narrowest particle size distribution and minimum size. • The state-of-art Pt/Co@N-CNTs exhibits superior both mass and specific activity towards to MOR. The surface microenvironment of supports, including surface state and constitution, are crucial adjective factors to the dispersibility and particle size of Pt nanoparticles (NPs) on carrier, follow-up affecting their catalytic activities for methanol oxidation reaction (MOR). Here an in-situ pyrolysis approach is reported for preparing bamboo-like N doped carbon nanotubes coupled with fewer metallic particles (M@N-CNTs (M = Co, Ni and Fe 3 C)), enabled tunable surface state and constitution of carbon layers. Combined experimental and theoretical investigation, as fabricated Co@N-CNTs provide optimal surface of backbone for Pt deposition with narrowest particle size distribution and minimum size by virtue of dominated pyridinic-N, enriched defect, abundant wrinkle and fewer number of carbon layer, which exhibits superior MOR performance as well as long-lifespan. Our findings not only exhibit some new insights for accurate modulation and optimization of carbon skelecton at the atomic scale in fundamental, but also reveal the structural and compositive origin of the enhanced catalytic activity towards to MOR. [ABSTRACT FROM AUTHOR]

Gas-liquid membrane contactor (GLMC) is a promising method to attain high efficiency for CO 2 capture from flue gas, biogas and natural gas. However, membranes used in GLMC are prone to pore wetting due to insufficient hydrophobicity and low chemical resistance, resulting in significant increase in mass transfer resistance. To mitigate this issue, inorganic-organic fluorinated titania/polyvinylidene fluoride (fTiO 2 /PVDF) composite hollow fiber (HF) membranes was prepared via facile in-situ vapor induced hydrolyzation method, followed by hydrophobic modification. The proposed composite membranes were expected to couple the superb chemical stability of inorganic and high permeability/low cost of organic materials. The continuous fTiO 2 layer deposited on top of PVDF substrate was found to possess a tighter microstructure and better hydrophobicity, which effectively prevented the membrane from wetting and lead to a high CO 2 absorption flux (12.7 × 10 −3  mol m −2  s −1 ). In a stability test with 21-day operation of GLMC using 1M monoethanolamine (MEA) as the absorbent, the fTiO 2 /PVDF membrane remained to be intact with a CO 2 absorption flux decline of ∼16%, while the pristine PVDF membrane suffered from a flux decline of ∼80% due to membrane damage. Overall, this work provides an insight into the preparation of high-quality inorganic/organic composite HF membranes for CO 2 capture in GLMC application. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman spectroscopy (SERS) as a powerful analytical tool has gained extensive attention. Despite of many efforts have been devoted to design SERS substrates, it still remains a grand challenge for creating a general substrate with high SERS active by a simple, controllable and low-cost way. Herein, we attempt to address this issue by fabricating SERS-active nano gold film based on self-assembly chemical plating composite method. The influence of gold colloid particle size on gold seed distribution density and the influence of the particle size of nano gold films on the SERS activity were investigated in detail. 10 −5 M Rhodamine 6G (R6G) was taken as Raman probe molecules and homemade Raman detection microsystem was used as detector. According to the results of SERS detection, the SERS substrate enhancement factors (SSEF) were calculated, and the nano gold film with average particle size of about 55 nm showed the maximum SSEF of 0.93 × 10 5 , which indicated such nano gold films showed excellent SERS activity. Moreover, these nano gold films are all low-cost and easy to prepared. This study provided theoretical and experimental basis for the design and preparation of general SERS substrate. [ABSTRACT FROM AUTHOR]