一步富氧煅烧法制备长可见光吸收的WO_(3)及其水氧化性能

Preparation and Performance of WO_(3)with Long Visible Light Absorption by One-Step Oxygen Enriched Calcination Method for Water Oxidation

三氧化钨(WO_(3))仅对460 nm以下波长的太阳光有响应,大大限制了其对太阳光的利用率。因此,如何拓宽WO_(3)的光谱响应范围是当前的研究重点。本文以仲钨酸铵[(NH_(4))10 H_(2)W_(12)O_(42)·xH_(2)O]为前驱体,通过一步富氧煅烧法制备了具有宽光谱可见光响应能力的N_(2)插入的纳米WO_(3)(N_(2)-WO_(3))。通过XRD、SEM、EDS、UV-Vis DRS、Raman等表征测试方法,研究了N_(2)插入对WO_(3)结构和性能的影响。结果表明:N_(2)插入有效地窄化了N_(2)-WO_(3)的禁带宽度(2.25 eV),较纯WO_(3)(2.76 eV)减小了0.51 eV;N含量对N_(2)-WO_(3)的可见光吸收能力有显著影响,且随着煅烧温度的升高N含量呈减小趋势。入射光子-电流转换效率(IPCE)的测试结果表明,N_(2)-WO_(3)可以对520 nm以下的可见光产生响应。光催化测试结果表明,N_(2)-WO_(3)的光催化活性优于纯WO_(3)。

Tungsten trioxide(WO_(3))only responds to sunlight below 460 nm,which greatly limits its utilization for sunlight.Therefore,the current research is focusing on broadening the spectral response range of WO_(3).In this paper,nitrogen intercalated WO_(3)(N_(2)-WO_(3))with wide spectrum visible light response was prepared by one-step oxygen enriched calcination method using ammonium paratungstate[(NH_(4))10 H_(2)W_(12)O_(42)·xH_(2)O]as precursor.The effects of N_(2)insertion on the structure and properties of WO_(3)were investigated by XRD,SEM,EDS,UV-Vis DRS and Raman.The results show that N_(2)insertion effectively narrows the band gap(2.25 eV)of N_(2)-WO_(3),which is 0.51 eV less than that of pure WO_(3)(2.76 eV);the N content has a significant effect on the visible light absorption capacity of N_(2)-WO_(3),and the N content decreases with the increase of calcination temperature.The measurement results of incident photon current conversion efficiency(IPCE)show that N_(2)-WO_(3)responds to visible light below 520 nm.The results of photocatalytic oxygen evolution show that the photocatalytic activity of N_(2)-WO_(3)is better than that of pure WO_(3).