Graphitic carbon nitride (g-C3N4) was prepared by pyrolysis of urea at different temperatures (450-650 °C), and characterized by thermogravimetric and differential thermal analysis (TG-DTA), elemental analysis (C/H/N), X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), Brunauer-Emmett-Teller (BET) analysis, Fourier transform-infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectra. The samples prepared at low temperatures (450 and 500 °C) are a mixture of g-C3N4 and impurities, whereas the samples prepared at high temperatures (550, 600 and 650 °C) should be g-C3N4 (polymeric carbon nitride). The polymerization degree of g-C3N4 for the prepared samples increases to a maximum at 600 °C with increasing pyrolysis temperature and then decreases, whereas the defect concentration changes conversely, that is, g-C3N4 prepared at 600 °C has the lowest defect concentration. Using Eosin Y (EY) and the prepared sample as the sensitizer and the matrix, respectively, the photocatalytic activity for hydrogen evolution from aqueous triethanolamine solution was investigated. The g-C3N4 prepared at 600 °C exhibits the highest sensitization activity. Under optimum conditions (1.25 × 10(-5) mol L(-1) EY and 7.0 wt% Pt), the maximal apparent quantum yield of EY-sensitized g-C3N4 prepared at 600 °C for hydrogen evolution is 18.8%. The highest activity can be attributed to the pure composition, the higher dye adsorption amount and the lowest defect concentration.

Mussel-inspired chemistry, as a powerful tool to manipulate material properties, has been widely studied and implemented in surface engineering of a variety of materials for multipurpose functionalization. With the rapid development of this field, more flexible and efficient modification strategies for surface engineering and application modes have been developed recently. It is therefore critical to update the broader scientific community on the important advances in this interdisciplinary field. Here, we summarize recent progress in musselinspired chemistry and its emerging applications in water remediation. The reaction and adhesion mechanisms of polydopamine, as well as its chemical and physical properties, are discussed. The functionalization strategies are categorized into post-functionalization, co-deposition, and pre-modification, and the roles of mussel-inspired surface coatings are highlighted in filtration, adsorbing, and catalytic materials as well as the burgeoning area of photothermal distillation materials.

CdS nanocrystals were synthesized by a hydrothermal method using ethylenediamine (en) as the template agent and coordination agent, and characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), BET, and UV−vis absorption spectroscopic techniques. Their photoactivity was evaluated by hydrogen evolution from aqueous solution containing formic acid as a hole scavenger under visible light (λ ≥ 420 nm) irradiation. The nanocrystals display rodlike and granular shapes, and their amount and morphology depend on the hydrothermal temperature and the added content of en. Photoactivity of the nanorods is higher than that of the nanograins. The effect of deposited Pt as cocatalyst on photoactivity for hydrogen evolution has been investigated. Pt can be dispersed highly on CdS so that the Pt content for effective hydrogen evolution is very low. 0.050 wt % Pt-loaded CdS shows the highest activity for hydrogen evolution under visible light irradiation, and the apparent quantum yield amounts to 13.9%. A possible mechanism was discussed.