Detecting and Quantifying Wavelength‐Dependent Electrons Transfer in Heterostructure Catalyst via In Situ Irradiation XPS

Abstract

The identity of charge transfer process at the heterogeneous interface plays an important role in improving the stability, activity, and selectivity of heterojunction catalysts. And, in situ irradiation X-ray photoelectron spectroscopy (XPS) coupled with UV light optical fiber measurement setup is developed to monitor and observe the photoelectron transfer process between heterojunction. However, the in-depth relationship of binding energy and irradiation light wavelength is missing based on the fact that the incident light is formed by coupling light with different wavelengths. Furthermore, a quantitative understanding of the charge transfer numbers and binding energy remains elusive. Herein, based on the g-C 3 N 4 /SnO 2 model catalyst, a wavelength-dependent Boltzmann function to describe the changes of binding energy and wavelength through utilizing a continuously adjustable monochromatic light irradiation XPS technique is established. Using this method, this study further reveals that the electrons transfer number can be readily calculated forming an asymptotic model. This methodology provides a blueprint for deep understanding of the charge-transfer rules in heterojunction and facilitates the future development of highly active advanced catalysts.

Two-Dimensional Atomically Thin Titanium Nitride via Topochemical Conversion

“…The Ti 2p bonds of the sample after irradiation for 100 s are moved negatively of ∼0.2 eV compared with that before irradiation (Figure d). This phenomenon illustrates that the UV laser irradiation can directly affect the migration of photogenerated electrons which induced the change of binding energy . Moreover, the Ti–N bonds significantly grow and the O–Ti–N doublets obviously decrease after the UV irradiation, which suggest that the chemisorbed oxygen has been removed by UV irradiation.…”

“…This phenomenon illustrates that the UV laser irradiation can directly affect the migration of photogenerated electrons which induced the change of binding energy. 38 Moreover, the Ti−N bonds significantly grow and the O−Ti−N doublets obviously decrease after the UV irradiation, which suggest that the chemisorbed oxygen has been removed by UV irradiation. Therefore, the as-prepared titanium nitride nanosheets are recognized as the titanium nitride with oxygen terminations which is similar to the structure of MXenes.…”

“FeV-cofactor”-inspired bionic Fe-doped BiVO4photocatalyst decorated with few-layer 2D black phosphorus for efficient nitrogen reduction

“…The XPS analysis provides information about the valence states and elemental composition of the BiVO 4 and FeBiVO 4 -0.05BP samples, 38 as shown in Fig. 4.…”

Revealing the Selective Bifunctional Electrocatalytic Sites via In Situ Irradiated X‐Ray Photoelectron Spectroscopy for Lithium–Sulfur Battery

“…Second, if we could couple an in situ characterization system to directly detect the charge transfer during the catalytic reaction, the distribution of potential electrocatalytic sites would be further confirmed. In situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) was first employed for the investigation of the charge transfer pathway of photogenerated electrons by our group, [37][38][39][40] which will satisfy this requirement because it can illustrate whether a particular component in the catalysts gains or loses electrons by comparing the binding energies of corresponding elements with and without light excitation during the testing process. [37] Therefore, it is challenging but desirable to develop a system that couples the additional physics gain effect with in situ characterization technique to synergistically convert the "black box" battery into a "see-through" battery for direct observation of the electrocatalytic reaction routes and sites.…”