Considering the high charge recombination rate, low optical adsorption intensity and limited active sites greatly constrict the solar‐to‐chemical conversion efficiency of polymer carbon nitride. Herein, a facile approach is reported to produce defected polymeric carbon nitride (PCN) with abundant granular bulks with fractured boundaries by thermal reduction treatment in CO atmosphere. The photocatalytic hydrogen evolution over defected PCN exhibits a rate of 3281.2 μmol g−1 h−1, 3.5 times higher than the pristine, which is most possibly ascribed to the following factors. The unique defected and porous structure not only provides higher specific surface area, more exposed active edges, abundant charge separation sites, and active centers for hydrogen generation but also is beneficial to rapid mass and charge transfer, interior diffusing of incident light, and shortening carrier transport length, thus enhancing the optical adsorption and accelerating the photocatalytic reaction kinetics. Furthermore, the electron delocalization at carbon vacancies sites on one hand facilitates the separation rate of electron–hole pairs and prolonged the carrier lifetime; on the other hand, the electronic polarization caused by C atoms loss helps increasing the affinity between catalyst and substrate reactant. Moreover, the higher electron donor density and lower conduction band minimum (CBM) potential further enhance the reduction capacity for H2 evolution.

Frost accumulated on the surface of the evaporator leads to the increase of heat transfer resistance between the refrigerant and environmental medium, which reduces the system performance of cold storage and air source heat pump. To solve this problem, the surface-modified evaporator can achieve retardation of the frost formation, which greatly improves the heat exchange effect between the refrigerant and the external environment. In this paper, a novel coating sprayed on the evaporator was developed using the sol-gel method and the hydrophobicity, durability, and thermal conductivity were investigated. Moreover, a modified method of frost weight measurement under different temperatures and humidity was first proposed. The results showed that the coating has a favorable hydrophobic effect and thermal conductivity, and long service life. Under the standard experimental condition, the frost weight on the coating surface can be reduced up to 26.1 %. Additionally, the effect of coating composition ratio on its performance was further investigated. To sum up, this new coating has the potential for industrialized application.

In order to alleviate the problem of high-temperature fly ash corrosion and slag on the heating surface of a high-parameter waste incinerator, a ceramic coating material that can be prepared in situ on the heating surface by the slurry method was studied. The ceramic coating can be formed by sintering at a lower temperature of 750 °C. Its surface and profile are very dense, and the porosity is less than 1%. The mechanical properties test results show that the ceramic coating can withstand 60 cycles of water-cooled thermal shock at 700 °C, and the bonding strength is 25.14 ± 2.21 MPa. It will not fall off in a large area when subjected to pressure load, and it has a certain degree of processable plasticity. High-temperature wettability experiments show that the ceramic coating has lower liquid-bridge force, smaller adhesion area, and shorter fouling cycle for molten corrosive fouling, and potential self-cleaning properties. Its practical mechanical properties make the coating valuable for production applications and meet expectations, and excellent antifouling properties to reduce average fouling thermal resistance and corrosion.

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