Enhanced Visible‐Light‐Driven Activity of Sodium‐, Calcium‐ and Aluminium‐Inserted g‐C3N4

• Published in: ChemistrySelect (Weinheim) 2018-10, Vol.3 (40), p.11241-11250
• Main Authors: Islam, M. Merajul, Tentu, Rama D., Ali, M. Asif, Basu, Suddhasatwa
• Format: Article
• Language: English
• Subjects: dye degradation; intercalated g-C3N4; OER; photocatalysis; photoelectrochemical
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.201802650

g‐C3N4 has emerged as a promising low‐cost metal free photocatalyst with ideal optical‐electronic properties; however, high recombination rate is one of the barriers associated with its low photocatalytic activity. Al and Ca intercalated g‐C3N4 photocatalysts with superior visible‐light utilization and charge‐carrier have been synthesized using one‐step thermal condensation method. An enhanced visible‐light harvesting capacity due to a red shift in the optical band gap of inserted g‐C3N4 photocatalysts was observed. The charge‐transfer, its kinetics across the interface and electron‐hole pairs separations were systematically investigated using photoelectrochemical measurements. The evaluation of photocatalytic activity of Al and Ca intercalated g‐C3N4 through degradation of RhB dye revealed 4.6 and 2.5 fold improvement in performance of g‐C3N4. Al intercalated g‐C3N4 shows highest photocurrent density, lowest Tafel slope and highest exchange‐current density due to least recombination rate of photo generated charge‐carriers, facile kinetics and least charge‐transfer resistance without use of any noble metal co‐catalyst towards oxygen evolution reaction (OER) with excellent stability. Al and Ca intercalated g‐C3N4 and Na‐doped g‐C3N4 were successfully synthesized using one‐step thermal condensation method. Intercalated Al atoms tend to form more effective extended π‐conjugated systems due to bridging of adjacent g‐C3N4 layers which leads to lower value of charge‐transfer resistance, most facile charge‐transfer and most effective charge separation. Al intercalated g‐C3N4 shows most enhanced visible‐light driven photocatalysis towards dye degradation and photoelectrochemical OER without noble metal co‐catalyst.