Using renewable H₂ for CO₂ hydrogenation to methane not only achieves CO₂ utilization, but also mitigates the greenhouse effect. In this work, several Ni-based catalysts with V species using 3D-mesoporous KIT-6 (Korea Advanced Institute of Science and Technology, KIT) as support were prepared at different contents of NiO and V₂O₅. Small Ni nanoparticles with high dispersibility on 20Ni-0.5V/KIT-6 were identified by X-ray diffraction (XRD), TEM and hydrogen temperature-programmed desorption (H₂-TPD) analysis, which promoted the production of more Ni active sites for enhancing catalytic activity for CO₂ methanation. Moreover, TEM and hydrogen temperature-programmed reduction (H₂-TPR) characterizations confirmed that a proper amount of Ni and V species was favorable to preserve the 3D-mesoporous structure and strengthen the interaction between active Ni and KIT-6. The synergistic effect between Ni and V could strengthen surface basicity to elevate the ability of CO₂ activity on the 20Ni-0.5V/KIT-6. In addition, a strong interaction with the 3D-mesoporous structure allowed active Ni to be firmly anchored onto the catalyst surface, which was accountable for improving catalytic activity and stability. These results revealed that 20Ni-0.5V/KIT-6 was a catalyst with superior catalytic activity and stability, which was considered as a promising candidate for CO₂ hydrogenation to methane.

Ag nanoparticles displayed a more attractive application in solar-driven interfacial evaporation for seawater desalination, but their synthesis process was expensive and detrimental to the environment due to the consumption of chemicals. In this work, we green-synthesized Ag nanoparticles using watermelon peel extract as reducing agent, while the membrane with Ag nanoparticles was prepared for solar-driven interfacial evaporation. Moreover, the evaporation performance of the membranes with different Ag nanoparticles loadings was investigated, as well as the reusability and desalination application was also explored. The experimental results showed that the membrane with Ag nanoparticles loading of 0.05 g exhibited superior evaporation performance, corresponding to the evaporation rate of 1.37 kg m⁻²h⁻¹ and the evaporation efficiency of 89.3%, respectively. In addition, the membrane with Ag nanoparticles possessed an excellent recyclability and concentration of ions in the desalinated seawater reached the potable water standard. Our research demonstrated that Ag nanoparticles green-synthesized by watermelon peel extract was an ideal candidate applied in solar-driven interfacial evaporation for seawater desalination.

In this work, an in situ carbonization technique was employed using a dehydration reaction to construct an evaporator with a bilayer structure using polyvinyl alcohol (PVA) sponge as the raw material for solar-driven interfacial evaporation. Its top layer was uniformly covered with carbon species prepared from dehydration of the PVA sponge, which promoted light capture to warm water for steam generation. Meanwhile, its interconnected porous structure remained intact after carbonization of the PVA sponge and was accompanied by the presence of some oxygen-containing functional groups, which preserved its hydrophilicity. Furthermore, its bottom layer shared the micro-scale porous characteristic and favorable hydrophilicity of the pristine PVA sponge. The results illustrated that the prepared CS-3 evaporator was provided with remarkable evaporation performance, mirroring an evaporation rate of 1.38 kg m⁻² h⁻¹. Additionally, a stable evaporation rate at around 1.36 kg m⁻² h⁻¹ was observed during the 10-cycle test. More importantly, the water desalinated from seawater was drinkable, which met the World Health Organization (WHO) standard. Consequently, it can be concluded that the evaporator developed using in situ carbonization of PVA sponge possessed many development prospects in the field of seawater desalination.