As a new organic photocatalyst, polymeric carbon nitride (CN) has shown good application potential in the field of photoelectrochemistry due to its unique physical and chemical properties, but its application has been seriously hindered due to its inherent characteristics such as the difficulty in charge separation. In this study, FeOOH modified CN photoanode (CN-Fe) was constructed to investigate the effect of the cocatalyst on the charge injection capacity of organic semiconductor photoelectrodes. The experimental results demonstrate significant improvement in the charge injection efficiency of the photoanode due to the introduction of FeOOH cocatalyst, leading to enhanced photoelectrochemical performance with approximately 2.4 times increase in photocurrent density. By thoroughly investigating the mechanism behind the loading of FeOOH on the polymeric carbon nitride photoanode, we gained profound insights into the behavior of charge carriers and reaction kinetics during the photoelectrocatalytic process.
Ba 0.6 Sr 0.4 Ti O 3 (BST) thin films doped by K (BSTK) from 1to20mol% were fabricated by sol-gel method on a Pt∕TiO2∕SiO2∕Si substrate. Thermal evolutionary process of the Ba0.6Sr0.4TiO3 and (Ba0.6Sr0.4)0.95K0.05TiO3 dry gel was carried out by thermogravimetry and differential thermal analysis system. The structure and surface morphology of BST thin films were investigated as functions of K concentration by x-ray diffraction and atomic force microscopy. The dielectric measurements were conducted on metal-insulator-metal capacitors at the frequency from 100Hzto1MHz. The K concentration in BST thin films has a strong influence on the material properties including surface morphology and dielectric and tunable properties. The grain size, surface root-mean-square roughness, dielectric constant, dissipation factor, and tunability all increased with increasing K content up to 7.5mol% and then decreased with increasing K content from 7.5to20mol% in the BSTK thin films at 1MHz. The effects of K doping on the microstructure and dielectric and tunable properties of Ba0.6Sr0.4TiO3 thin films were analyzed. The (Ba0.6Sr0.4)92.5%K7.5%TiO3 thin film exhibited the highest dielectric constant of 1040 and the largest tunability of 73.6%. The dielectric constant, dielectric loss, and tunability of K-doped BST thin films with the optimal K content of 5mol% were about 971, 0.023, and 69.96%, respectively. In addition, its figure of merit showed a maximum value of approximately 28.52.
A PTB7-based cationic narrow band-gap polyelectrolyte, named PTB7-NBr, has been designed and synthesized as a cathode interfacial material for polymer solar cells. PTB7-NBr exhibits excellent cathode interfacial modification in solar cells with PTB7 and PTB7-Th as donor polymer and a high PCE of 9.24% was achieved.