Yajun Zhang

Defect engineering is a promising strategy in heterogeneous catalysis, while understanding how the defective sites affect reactivity still remains ambiguous. Herein, we demonstrated an in‐depth experimental study of dynamic interaction of CO ₂ molecules on defective In ₂ S ₃ surfaces by integrating operando X‐ray photoelectron spectroscopy with infrared spectroscopy. More specifically, the formation of S vacancy could promote the electron enrichment on adjacent In sites for facilitating CO ₂ molecule adsorption, accompanying with the emergence of high oxidation states of surface In sites. Upon light illumination, the adsorbed CO ₂ molecules undergo a sequential transformation into *COOH and *CO intermediates. However, an unexpected upside‐down inversion of *CO species on defective In sites from In–*CO to In–*OC has been firstly observed, severely restraining desorption of CO product from In ₂ S ₃ surfaces. Further tailoring the electronic structure of defective In sites by substituting residual S atom with O atom for inhibiting *CO inversion, a significant improvement of CO evolution activity has been achieved (18.3 µmol g ⁻¹ h ⁻¹ ), nearly five times higher than that of pristine In ₂ S ₃ (3.77 µmol g ⁻¹ h ⁻¹ ). This work provides the new insights on dynamic roles of defect‐derived active sites in determining catalytic activity, which might offer opportunities for fine control of catalytic process.

A facile strategy has been reported for anchoring Co single atoms on BiOCl nanosheets to enable efficient CO₂ photoreduction, and the neighboring effect of single-atom cobalt has been clarified by in situ X-ray photoelectron spectroscopy.

We demonstrated a facile electrochemical treatment for in situ anchoring of Cu ₄ clusters in a graphitic C ₃ N ₅ framework, leading to remarkable improvements of photocatalytic reactivity and selectivity towards CO ₂ reduction to ethanol.

The intelligent design or development of dual‐functional catalysts using non‐precious metals especially for the oxygen evolution reaction (OER) in sustainable energy systems and degradation of organic pollutants is still a difficult and a significant challenge. Furthermore, the development of these catalysts is of great importance in terms of energy security and solution of the environmental problems. To meet these requirements, herein, we describe the synthesis of a Ni‐ion doped Birnessite@Cryptomelane (Ni²⁺/B@Cr) hybrid structure as a bifunctional efficient catalyst for the OER in neutral media and degradation of dye pollutants. The Ni²⁺/B@Cr catalyst exhibited a sharp onset potential at 390 mV (vs. RHE) and achieved a current density of 1 mA cm⁻² at a low ƞ of 430 mV with a Tafel slope of ~96 mV dec⁻¹. The results of electrochemical impedance spectroscopy (EIS) studies indicated that Ni intercalation into birnessite layer and heterostructure of the hybrid electrocatalyst Ni²⁺/B@Cr increased the conductivity by lowering the resistance of charge transfer (R_ct = 4.82 Ω) and oxygen evolution processes (R_OER = 4.13 Ω). The durability assay identified Ni²⁺/B@Cr as stable electrocatalyst with 10% loss of activity after long‐term stability tests (10 h, under 500‐mV overpotential). In addition, the Ni²⁺/B@Cr achieved high (86.67 s⁻¹ g⁻¹) and rapid (173 s) catalytic performance for the reduction of methylene blue (MB). Overall, this paper presents a low‐cost production strategy for the design of highly efficient bifunctional catalysts, offering boosted electrocatalytic and degradation performance for water oxidation and organic dye contamination, respectively.

The combination of time-resolved transient photoluminescence with in-situ Fourier transform infrared spectroscopy has been conducted to investigate the intrinsic phase structure-dependent activity of Bi₂O₃ catalyst for CO₂ reduction.

Photoelectrochemical (PEC) water splitting is a promising method for storing solar energy in the form of hydrogen fuel, but it is greatly hindered by the sluggish kinetics of the oxygen evolution reaction (OER). Herein, a facile solution impregnation method is developed for growing ultrathin (2 nm) highly crystalline β‐FeOOH nanolayers with abundant oxygen vacancies on BiVO₄ photoanodes. These exhibited a remarkable photocurrent density of 4.3 mA cm⁻² at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5 G), which is approximately two times higher than that of amorphous FeOOH fabricated by electrodeposition. Systematic studies reveal that the excellent PEC activity should be attributed to their ultrathin crystalline structure and abundant oxygen vacancies, which could effectively facilitate the hole transport/trapping and provide more active sites for water oxidation.