Pyrrole-assisted molecular engineering of cellulose-derived polyfuran photocatalysts for efficient H2O2 production

Hydrothermal carbonaceous carbon (HTCC) has been widely used in photocatalytic H 2 O 2 production due to its green sustainability and favorable semiconductive property, which, however, still suffer from slow separation of photogenerated carriers and low energy utilization. Herein, we have successfully constructed a new type of pyrrole-doped HTCC (Py/HTCC) photocatalyst with cellulose directly extracted from natural balsa wood and pyrrole as raw materials for boosting H 2 O 2 photosynthesis. The strong π-conjugated structure of Py/HTCC formed by the stacking of electron donors (furan units) and acceptors (pyrrole units) can not only accelerate the intramolecular charge transfer to achieve a low band gap and efficient light adsorption, but also significantly decrease the particle size to expose abundant active sites. Benefitting from its high energy utilization, low reaction energy barrier, accelerated oxygen reduction kinetics and desirable photothermal-assisted effect, the optimized Py/HTCC shows a high H 2 O 2 generation rate of 1437.7 μmol·g −1 ·h −1 in pure water under simulated sunlight without sacrificial agents, which is 3.8 times that of its pyrrole-free HTCC counterpart (379.4 μmol·g −1 ·h −1 ) under the same conditions. Theoretical calculations reveal the furan-pyrrole-alternating π-conjugated structure can optimize the energy level structure of Py/HTCC, improve its separation efficiency of photogenerated carriers and enhance the adsorption/activation of oxygen, all of which contribute to its remarkedly-enhanced activity for H 2 O 2 photosynthesis. A new type of pyrrole-contained polyfuran photocatalysts with strong π-conjugated D-A pairs was successfully constructed by using cellulose directly extracted from natural balsa wood and pyrrole as raw materials for boosting H 2 O 2 photosynthesis in pure water. • A new pyrrole-doped HTCC photocatalyst is synthesized from wood-derived cellulose and pyrrole. • The furan-pyrrole alternating π-conjugated structure of Py/HTCC can accelerate charge transfer. • The desirable photothermal effect of Py/HTCC can further enhance the H 2 O 2 generation kinetics. • The optimized Py/HTCC shows a 3.8 times H 2 O 2 generation rate than its pyrrole-free counterpart.