Abstract：
The design and construction of highly efficient electrocatalysts for overall water splitting and urea electrolysis are significantly important for promoting energy conversion and realizing green hydrogen production. In this work, we constructed a multi-phase heterojunction through a simple hydrothermal and phosphorization process. The P-doped NiFe2O4 (P-NiFe2O4) nanoparticles were uniformly anchored on the bamboo-like N-doped carbon nanotubes (NCNTs) grown via a NiFe-alloy autocatalysis. The electronic structure and coordination environment of active species were optimized by the synergistic action of P doping, well-dispersed ultrafine NiFe2O4, and NCNTs matrix with good conductivity, enhancing their quantity and activity for electrocatalysis. Consequently, the P-NiFe2O4/NCNTs/NiFe exhibits excellent HER and OER activities with an overpotential of 111 and 266 mV at 10 mA cm-2 in 1 M KOH, respectively. The symmetrical overall water-splitting cell using P-NiFe2O4/NCNTs/NiFe as both anode and cathode delivers 10 mA cm-2 at a voltage of 1.604 V in 1 M KOH. Notably, the two-electrode cell requires a low voltage of 1.467 V to achieve a current density of 10 mA cm-2 in 1 M KOH solution with 0.6 M urea. This designed catalysts display outstanding reaction kinetics and catalytic stability. This work provides useful guidance for applying transition metal-based catalysts for hydrogen production.
摘要：
设计和建造用于整体水分解和尿素电解的高效电催化剂对于促进能量转化和实现绿色制氢具有重要意义。在这项工作中,我们通过简单的水热和磷化过程构建了多相异质结。掺杂P的NiFe2O4（P-NiFe2O4）纳米颗粒均匀地锚定在通过NiFe合金自催化生长的竹状N掺杂碳纳米管（NCNT）上。通过P掺杂的协同作用，优化了活性物种的电子结构和配位环境，分散良好的超细NiFe2O4和具有良好导电性的NCNTs基体，提高其电催化的数量和活性。因此,P-NiFe2O4/NCNTs/NiFe表现出优异的HER和OER活性，在1MKOH中10mAcm-2时的过电位为111和266mV，分别。使用P-NiFe2O4/NCNT/NiFe作为阳极和阴极的对称整体水分解电池在1MKOH中的1.604V电压下可提供10mAcm-2。值得注意的是,双电极电池需要1.467V的低电压才能在1MKOH溶液和0.6M尿素中实现10mAcm-2的电流密度。这种设计的催化剂表现出优异的反应动力学和催化稳定性。这项工作为过渡金属基催化剂用于制氢提供了有用的指导。
