TY - JOUR
T1 - Boron-functionalized graphitic carbon nitride materials for photocatalytic applications
T2 - effects on chemical, adsorptive, optoelectronic, and photocatalytic properties
AU - Itskou, Ioanna
AU - C. Sageer, Sharminaz
AU - Dawson, Daniel M.
AU - Kafizas, Andreas
AU - Nevjestic, Irena
AU - McGilvery, Catriona M.
AU - Daboczi, Matyas
AU - Kerherve, Gwilherm
AU - Eslava, Salvador
AU - Heutz, Sandrine
AU - Ashbrook, Sharon E.
AU - Petit, Camille
N1 - Funding: I.I. and C.P. would like to acknowledge funding for this study through the ERC Starting Grant THEIA (Project number: 850624) and to the Department of Chemical Engineering at Imperial College London for the PhD Departmental Scholarship. A.K. thanks the EPSRC for a Programme Grant (EP/W017075/1) and the Royal Society for an Equipment Grant (RSG/R1/180434). M.D. and S.E. acknowledge the EPSRC grant EP/S030727/1 for financial support. C.M.M. wants to acknowledge EPSRC for funding for the Cryo EPS facility strategic equipment grant EP/V007661/1. The authors would like to acknowledge the EPSRC equipment funding for SPIN-Lab (EP/P030548/1) (S.H. and I.N.). S.C.S would like to acknowledge funding from the Irvine Postgraduate Research Scholarship for Chemistry.
PY - 2025/5/12
Y1 - 2025/5/12
N2 - Graphitic carbon nitride (gC3N4, or CN herein) is widely studied as a photocatalyst owing to its ease of synthesis, high stability, and optoelectronic properties. However, its photocatalytic performance often remains limited, and a common approach to tune its function and enhance its performance is by doping. Boron (B) functionalization of CN has showed a potential benefit on photocatalytic performance for several reactions. However, the reason for this improvement and the links between synthesis method, exact B chemical environment, and performance remain unclear. Here, we present a fundamental study that elucidates the influence of (i) B functionalization, (ii) B content, and (iii) choice of B precursor on the physicochemical, adsorptive, optoelectronic, and photocatalytic properties of bulk B-CN. We synthesized two sets of B-CN materials (0.5–11 at% B), using either elemental boron or boric acid as precursors. The samples were characterized using several imaging and spectroscopic techniques, which confirm the integration of B into the material through B–O bonding and the creation of B clusters in the case of the boron precursor, with density functional theory (DFT) calculations supporting our analyses. The distribution of B atoms within B-CN particles remained heterogeneous. Compared to CN, B-functionalized materials show enhanced porosity and CO2 uptake, with similar degrees of light absorption and deeper energy band positions. Transient absorption spectroscopy (TAS) measurements showed that charge carrier populations, lifetimes, and kinetics were not significantly affected by B functionalization; however, at 5 at% B doping, an increase in the concentration of charge carriers was seen. Higher B content enhances the photocatalytic NOx removal under UVA irradiation (almost two-fold) and the selectivity to NO3– from NOx photooxidation, but has no significant effect on CO2 photoreduction, compared to pristine CN. Overall, this study provides fundamental insights to build on and more rationally produce better-performing B-CN photocatalysts.
AB - Graphitic carbon nitride (gC3N4, or CN herein) is widely studied as a photocatalyst owing to its ease of synthesis, high stability, and optoelectronic properties. However, its photocatalytic performance often remains limited, and a common approach to tune its function and enhance its performance is by doping. Boron (B) functionalization of CN has showed a potential benefit on photocatalytic performance for several reactions. However, the reason for this improvement and the links between synthesis method, exact B chemical environment, and performance remain unclear. Here, we present a fundamental study that elucidates the influence of (i) B functionalization, (ii) B content, and (iii) choice of B precursor on the physicochemical, adsorptive, optoelectronic, and photocatalytic properties of bulk B-CN. We synthesized two sets of B-CN materials (0.5–11 at% B), using either elemental boron or boric acid as precursors. The samples were characterized using several imaging and spectroscopic techniques, which confirm the integration of B into the material through B–O bonding and the creation of B clusters in the case of the boron precursor, with density functional theory (DFT) calculations supporting our analyses. The distribution of B atoms within B-CN particles remained heterogeneous. Compared to CN, B-functionalized materials show enhanced porosity and CO2 uptake, with similar degrees of light absorption and deeper energy band positions. Transient absorption spectroscopy (TAS) measurements showed that charge carrier populations, lifetimes, and kinetics were not significantly affected by B functionalization; however, at 5 at% B doping, an increase in the concentration of charge carriers was seen. Higher B content enhances the photocatalytic NOx removal under UVA irradiation (almost two-fold) and the selectivity to NO3– from NOx photooxidation, but has no significant effect on CO2 photoreduction, compared to pristine CN. Overall, this study provides fundamental insights to build on and more rationally produce better-performing B-CN photocatalysts.
KW - Graphitic carbon nitride
KW - Boron
KW - NMR spectroscopy
KW - XPS
KW - Photocatalysis
KW - NOx
KW - CO2
U2 - 10.1021/acsmaterialsau.5c00007
DO - 10.1021/acsmaterialsau.5c00007
M3 - Article
SN - 2694-2461
VL - ASAP
JO - ACS Materials Au
JF - ACS Materials Au
ER -