Photocatalytic nitrogen fixation has attracted extensive attention in recent years. Studies have shown that catalytic materials with O, N and other defects can effectively reduce the bond energy of NN triple bond when N₂ is adsorbed on the defects. As an outstanding non-metallic catalyst, g-C₃N₄ has been widely studied in the field of photocatalytic catalysis, and the nitrogen-defected C₃N₄ shows promoted photocatalytic activity. Herein, nano-size MOF-74 particles (<20 nm) was dispersed on nitrogen-defected C₃N₄ thin film (∼4 nm) via a simple sol–gel method. The combination of Nano-MOF and defected film C₃N₄ could effectively improve the photocatalytic activity of nitrogen fixation through Z-scheme mechanism compared with pure defected film C₃N₄.

Dark surface waves with photorefractive diffusion and photovoltaic nonlinearities are predicted for the first time. We find it is extraordinary that this type of dark surface waves should be in self-focusing media, which is very different from the surface dark solitons or other nonlinear dark surface waves. An oscillator model is proposed by which the above extraordinary phenomenon is demonstrated. In this model an equivalent force function is established, whose form determines the varieties of surface waves (bright surface waves, dark surface waves or others).

We introduce a type of $(2+1)D$ surface soliton in virtue of the cooperation of nonlocal and local nonlinearities. Furthermore, taking advantage of diffusion and drift nonlinearity this type of surface soliton is demonstrated theoretically and experimentally in a storintium barium nitrate crystal. The dynamics behavior of the excitation and propagation of this type of surface soliton are studied using the beam-propagation method and the nonlinear equation of light rays.

Markedly improved photocatalytic reduction of CO₂ by a porous porphyrin polymer was triggered by the synergic effect of hollowrization and sulfonation.

We report on the existence of surface dark screening solitons at the interface between a dielectric medium (air) and a self-defocusing nonlinear material, taking advantage of photorefractive diffusion and drift nonlinearities. It is very interesting that a surface dark soliton is just like half of a dark soliton in bulk, but not a whole dark soliton propagating along surface. The excitation, propagation, and stability of this type of soliton are studied by using the beam-propagation method. Another interesting thing is that this type of dark soliton can be excited by a planar light beam without a necessary dark notch.