Heterogeneous photocatalysis is an attractive enabler of the efficient execution of various im-portant environmental (e.g., hydrogen production and C-based fuel production) and organic reac-tions utilizing solar energy. In a typical batch reactor, a heterogeneous photocatalyst is dispersed in a given solution together with reactants, and upon illumination, a chemical reaction occurs. Despite its simplicity, the overall process faces some challenges related to the intrinsic nature of the reaction conditions: light penetration significantly decreases with distance, the photocatalyst should be continuously stirred to avoid sedimentation, separating the products from the photocata-lyst is not trivial, the catalyst is hard to recycle, the reaction is dependent on the concentration of starting reactants, and scalability is questionable.
An alternative approach is to use a panel based on a photocatalytic material. This configuration enhances light management and facilitates easy recycling and scalability, similar to that of solar cells. Furthermore, the photocatalyst panel can be easily incorporated into a continuous-flow re-actor, facilitating constant reactant feed and product separation. In recent years, polymeric carbon nitride (CN) materials have emerged as a class of photocatalysts for many reactions, from solar fuel production to biomass conversion and complex organic transformations. Nevertheless, most studies have focused on using CN powders as heterogeneous photocatalysts. Some pioneering works have shown the utilization of CN panels, primarily for H2 production. However, all these panels were prepared by drop-casting or screen-printing a synthesized catalyst with a polymer containing perfluoro groups (i.e., Nafion) or a SiO2 binder onto frosted glass or steel plates. The use of a binder can lead to photocatalyst detaching from the substrate due to the formation of radicals during the reaction, such as reactive organic species (ROS). This phenomenon primarily occurs in organic chemical reactions, where ROS intermediates can react with the binder to pro-duce unwanted byproducts.
This talk will introduce facile and scalable approaches for growing polymeric carbon nitride (CN) layers on conductive substrates with tunable structural and photophysical properties for photocata-lytic applications. We demonstrate CN-based photocatalytic panels as highly stable, efficient plat-forms for converting organic molecules into value-added chemicals while simultaneously produc-ing hydrogen and hydrogen peroxide. Additionally, I will demonstrate the use of CN-films as highly stable photocatalytic panels for various catalytic and cascade reactions.