Abundant pyridinic nitrogen in the triazine units of covalent triazine frameworks (CTFs) is very useful in various heterogeneous catalysis reactions. Herein, a tunable CTF platform with the same porous structure was designed and synthesized to study the interaction between palladium/platinum (Pd/Pt) and pyridinic nitrogen of CTFs. The smaller Pd nanoparticles were formed because of the stronger interaction between Pd and pyridinic nitrogen atoms of CTFs, which is more beneficial for the separation of photogenerated electron-hole pairs. Moreover, the stronger interaction between the Pd nanoparticles and CTFs is also beneficial for photoelectron transfer. Under the same conditions, the hydrogen evolution rate of 1 wt % Pd@CTF-HC6 is up to 11 times more than that of 1 wt % Pt@CTF-HC6. The hydrogen evolution rate of 1 wt % Pd@CTF-N approaches 10 556 μmol h-1 g-1 and is about 5 times more than that of 1 wt % Pt@CTF-N.
Keywords: cocatalyst; covalent triazine frameworks; hydrogen evolution; palladium; photocatalysis; water splitting.