Critical Optimization of Phosphorus Functionalized Carbon Nanomaterials for Metal‐Free Solar Hydrogen Production and Simultaneous Organic Transformation

Abstract

Complete metal‐free P‐functionalized carbon nanomaterials are synthesized from a single molecular precursor, phytic acid, for photocatalytic solar H2 production and simultaneous organic transformation of 4‐methyl benzyl alcohol to 4‐methyl benzaldehyde by managing the complete redox cycle. It is observed that by increasing the carbonization time, P‐functionalized amorphous carbon dots convert to the highly defined 2D sheet‐like nanostructure with optimum P‐functionality, resulting in efficient light absorption, charge separation, and improved active sites for photocatalysis. Finally, the highly defined sheet‐like structure converts to a more defected aggregated form, resulting in the depletion of photocatalytic efficiency. The structural and elemental features are further correlated with the ongoing photophysics by means of steady‐state and time‐resolved fluorescence spectroscopy. Transient photocurrent responses and Mott‐Schottky plots directly support the optimization of P‐functionalized carbon nanostructure for efficient photocatalysis. Finally, the detailed computational studies are carried out to unveil the charge separation mechanism and the crucial role of P‐functionalities as active sites for better charge accumulation as well as H2O adsorption on the surface. Overall, the in‐depth structure–property correlation and critical optimization of the heteroatom functionalized carbon nanomaterials will open up new possibilities for further development of metal‐free photocatalysts for solar‐energy conversion devices.

Switching between Fluorescence and Room Temperature Phosphorescence in Carbon Dots: Key Role of Heteroatom Functionalities

“…In the case of P-CDs, the emission maxima are further red-shifted, which indicates the formation of a new energy levels or an intermediate trap state for electron transitions due to more defect states. 64 It is further supported by the graphical representation of the variation of PL emission maxima upon varying the excitation wavelengths from 300 to 500 nm (Figure S8d). 65,66 For further clarification, we performed detailed time-resolved fluorescence lifetime measurements at 340 nm excitation wavelength (depicted in Figure 3d).…”

Recent Advances in g-C3N4-Based Materials and Their Application in Energy and Environmental Sustainability

“…Nevertheless, 85% of H 2 is produced from fossil fuel combustion, which generates roughly 500 metric tons of carbon dioxide every year and proffers a challenge and obstacle toward the sustainable living of future generations [ 132 ]. Solar-driven photocatalytic H 2 generation as a promising technology has received extensive attention in addressing the global energy crisis [ 133 , 134 ]. Photocatalytic water splitting for the energy transformation from solar to eco-friendly fuels has been studied for decades with various semiconductor photocatalysts.…”

Accelerating NADH oxidation and hydrogen production with mid-gap states of nitrogen-rich carbon nitride photocatalyst

“…Here, the D band denotes the degree of defect sites in the graphitic domain, whereas the G band corresponds to the sp 2 aromatic domain. 26 The number of defects can be elucidated by the relative intensity ratio of I D /I G . In the case of NPCN, the I D /I G ratio increased from 0.35 (PCN) to 0.41, which denotes the presence of excess defects in NPCN than PCN.…”