Delete data from the table after renaming column Laravel 5.8 - php

Question

Recently I've started with Laravel 5.8 and I'm trying to make the delete button which will delete row from the database. But before I create the button, I've Already Change the column id name in the table from id to id_book, the problem is Laravel still get the id-data, not id_book, and raise an error
like this
**Column not found: 1054 Unknown column 'books.id'**
this is button's code:
<form action="/hapus/{{ $book->id_book }}" method="POST">
#method('DELETE')
#csrf
<input type="submit" value="Hapus">
</form>
this is the Controller's Method:
public function hapus($id_book){
$book = Books::find($id_book);
$book->id;
if($book->gambar = 1){
Storage::delete($book->gambar);
$book->delete();
return redirect('/books');
}
else{
$book->delete();
return redirect('/books');
}
the column in tables is:
id_book (previously is id),
name,
image,
category,
description
thank for help, this is my model after fixing this problem:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Books extends Model
{
protected $table = "books";
protected $primaryKey = "id_book";//solution
protected $fillable = [
'title',
'images',
'category',
'description'
];
}