Room-temperature pyro-catalytic hydrogen generation of 2D few-layer black phosphorene under cold-hot alternation

Abstract

Many 2D few-layer materials show piezoelectric or pyroelectric effects due to the loss-of-inversion symmetry induced by broken structure, although they are not piezoelectric or pyroelectric in the bulk. In this work, we find that the puckered graphene-like 2D few-layer black phosphorene is pyroelectric and shows a pyro-catalytic effect, where the pyroelectric charges generated under ambient cold–hot alternation are utilized for hydrogen evolution and dye molecule decomposition. Under thermal cycling between 15 °C and 65 °C, the 2D few-layer black phosphorene shows a direct hydrogen generation of about 540 μmol per gram of catalyst after 24 thermal cycles and about 99% decomposition of Rhodamine B dye after 5 thermal cycles. This work opens a door for the pyro-catalytic energy harvesting from the cold–hot alternations by a class of 2D few-layer materials.

Catalysis Mediated by 2D Black Phosphorus Either Pristine or Decorated with Transition Metals Species

“…When compared to its single components, the ternary heterostructure showed much higher activity under visible light illumination and allowed for extending the photocatalytic activity to embrace the near-infrared region, reaching H 2 production rates of 0.74 and 0.30 mmol g −1 h −1 at wavelengths longer than 420 and 780 nm, respectively. To unravel the reason behind such extended photoresponse, time-resolved diffuse reflectance spectroscopy was measured and it revealed efficient interfacial electron transfer from excited BP and Au to LTO, which is in agreement with the observed activity, being superior to recently published data shown in Sections 4.1 and 5.4 [56,58,59,84]. This opens the possibility of application of BP to challenging processes based on solar-energy conversion.…”

“…In a seminal work by You H. et al, [59] it was discovered that 2D BP is a pyroelectric material and this physical property can be of great advantage in catalysis. Indeed, it was shown that 2D BP, once suspended in water in the dark, can afford a direct hydrogen evolution of approximately 540 µmol h −1 per gram of catalyst, after 24 thermal cycling between 15 • C and 65 • C. The reason behind it is that the cold-hot alternation excitation induces a net change of the electric dipole moment in the material, thus positive and negative charges are created.…”

“…These results open new avenues in the application of 2D BP as pyrocatalyst, not only for the HER process. The current protocol by You H. et al [59] can be improved by also exploiting the photocatalytic activity of BP, which, in synergy with the capacity of heat energy harvesting, might greatly enhance the production rate of hydrogen from water.…”

Enabling PIEZOpotential in PIEZOelectric Semiconductors for Enhanced Catalytic Activities

“…The amount of hydrogen generated reached 46.89 μmol g −1 after 36 thermal cycles from 298 to 323 K . Moreover, the puckered 2D few‐layer black phosphorene exhibits approximately 99 % degradation of RhB after 5 cold–hot cycles from 288 to 338 K, and a direct hydrogen evolution of 540 μmol g −1 catalysts after 24 thermal cycles . More examples of pyroelectric catalysis are summarized in Table .…”

Pyroelectrocatalytic CO2 reduction for methanol driven by temperature-variation

“…Similar to the photocatalysis, pyroelectrocatalytic process can produce positive and negative charges by using pyroelectric materials as the active media during temperature variation. The energy generated through such a process has been applied to some catalytic process such as dye decomposition [14][15][16] and water splitting 17,18 . Theoretical calculation shows that a pyroelectric engine in an ideal condition can reach an energy conversion e ciency as high as 84-92%, which is much higher than the photovoltaic energy conversion e ciency typically in the range of 20% 19,20 .…”