The modulation of the electronic structure is the effective access to achieve highly active electrocatalysts for the hydrogen evolution reaction (HER). Transition-metal phosphide-based heterostructures are very promising in enhancing HER performance but the facile fabrication and an in-depth study of the catalytic mechanisms still remain a challenge. In this work, the catalytically inactive n-type CeOx is successfully combined with p-type CoP to form the CoP/CeOx heterojunction. The crystalline-amorphous CoP/CeOx heterojunction is fabricated by the phosphorization of predesigned Co(OH)2/CeOx via the as-developed reduction-hydrolysis strategy. The p-n CoP/CeOx heterojunction with a strong built-in potential of 1.38 V enables the regulation of the electronic structure of active CoP within the space-charge region to enhance its intrinsic activity and facilitate the electron transfer. The functional CeOx entity and the negatively charged CoP can promote the water dissociation and optimize H adsorption, synergistically boosting the electrocatalytic HER output. As expected, the heterostructured CoP/CeOx-20:1 with the optimal ratio of Co/Ce shows significantly improved HER activity and favorable kinetics (overpotential of 118 mV at a current density of 10 mA cm-2 and Tafel slope of 77.26 mV dec-1). The present study may provide new insight into the integration of crystalline and amorphous entities into the p-n heterojunction as a highly efficient electrocatalyst for energy storage and conversion.

Boosting Hydrogen Evolution Electrocatalysis via Regulating the Electronic Structure in a Crystalline-Amorphous CoP/CeOx p-n Heterojunction.

Hierarchical 3D flower like cobalt hydroxide as an efficient bifunctional electrocatalyst for water splitting

Construction of CoNiSSe-g-C3N4 nanosheets with high exposed conductive interface for boosting oxygen evolution reaction

Defect and interface engineering of templated synthesis of hollow porous Co3O4/CoMoO4 with highly enhanced electrocatalytic activity for oxygen evolution reaction

To alleviate the fast recombination of charges and enhance the stability of CdS, a novel [email protected] aluminum hydroxide (AAH) cocatalyst was developed and loaded on CdS nanorods via an in-situ phosphorization process to structurally separate the photogenerated carriers. The AAH completely covers the CdS nanorods to form a core-shell structure, and the high-conductivity CoP nanoparticles embedded in the AAH shell act as a charge transfer bridge, making the H2 evolution reaction sites migrate far from CdS and thus prevent the photocorrosion derived from the accumulation of photogenerated holes. The optimized CdS/[email protected] hybrid catalyst presents a photocatalytic H2 evolution rate of 54.9 mmol/g/h, apparent quantum efficiency of 40.62% and excellent cycle stability. DFT calculations were also employed from the views of band structure and Gibbs free energy to illuminate the photocatalytic mechanism. This work offers a new strategy to restrain the photocorrosion and enhance the photocatalytic H2 production of CdS-based catalysts simultaneously. 

A novel CoP@AAH cocatalyst leads to excellent stability and enhanced photocatalytic H2 evolution of CdS by structurally separating the photogenerated carriers

Spontaneously engineering heterogeneous interface of silver nanoparticles on α-Co(OH)2 for boosting electrochemical oxygen evolution

Exploring high-efficiency and earth-abundant bifunctional electrocatalysts for overall water splitting is of great significance to meet the requirement of the hydrogen economy, but still faces many...

Hollow CoP Encapsulated in an N-Doped Carbon Nanocage as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting

Hierarchical particle-on-sheet CoP fabricated by direct phosphorization of Co(OH)2/ZIF-67 hybrid for boosting hydrogen evolution electrocatalysis

Interface Engineering in CoP/CePO4 Derived from a Prussian Blue Analogue as a Highly Efficient Electrocatalyst for Alkaline Hydrogen Evolution Reaction

The confined growth of ZIF-67 (ZIF = zeolitic imidazolate framework) on α-Co(OH)2 nanosheets has been successfully achieved. The interface coupling in α-Co(OH)2/ZIF-67 would regulate the electrochemical environment of cobalt at the interface and expose more active sites. As a result, the optimal α-Co(OH)2/ZIF-67-0.6 catalyst exhibits higher activity (η10 = 320 mV), fast kinetics (Tafel slope of 109.3 mV dec−1), and excellent durability after continuous operation for 24 h.

Zan-Yao Niu

Papers

Spontaneously engineering heterogeneous interface of silver nanoparticles on α-Co(OH)2 for boosting electrochemical oxygen evolution

Hollow CoP Encapsulated in an N-Doped Carbon Nanocage as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting

Hierarchical particle-on-sheet CoP fabricated by direct phosphorization of Co(OH)2/ZIF-67 hybrid for boosting hydrogen evolution electrocatalysis

Interface Engineering in CoP/CePO4 Derived from a Prussian Blue Analogue as a Highly Efficient Electrocatalyst for Alkaline Hydrogen Evolution Reaction

Interface engineering in the α-Co(OH)2/ZIF-67 heterostructure for enhanced oxygen evolution electrocatalysis